{"id":"https://data.mapsnap.org/runs/v1.3/iiif/chronoscope/sanborn01701_004.main.iiif.json","type":"AnnotationPage","@context":["http://www.w3.org/ns/anno.jsonld"],"label":"Alton, Illinois | 1902 | mapsnap generated fit (2026-09-23)","creator":{"type":"Software","name":"mapsnap","homepage":"https://mapsnap.org"},"rights":"https://opendatacommons.org/licenses/odbl/1-0/","metadata":[{"label":"generated","value":"2026-09-23"},{"label":"run","value":"corpus-v1"},{"label":"pages","value":"37"},{"label":"placed","value":"21"},{"label":"unplaced","value":"16"},{"label":"fit sources","value":"georef 10, georef-snap 9, snap:0 2"},{"label":"key map","value":"georeferenced"},{"label":"split sheets","value":"6 sheet(s) cut into 23 panels"},{"label":"unplaced pages","value":"p1 (tier 1, 38.89148,-90.16610 +/-283m); p13 (tier 1, 38.88705,-90.16516 +/-269m); p14__1 (tier 1, 38.89746,-90.18122 +/-287m); p14__3 (tier 2, 38.88915,-90.15865 +/-100m); p16__1 (tier 3, 38.89443,-90.17108 +/-1138m); p16__4 (tier 1, 38.88902,-90.16158 +/-100m); p17__1 (tier 1, 38.90182,-90.18541 +/-110m); p17__2 (tier 1, 38.89858,-90.18757 +/-108m); p18__3 (tier 1, 38.89790,-90.18949 +/-100m); p18__4 (tier 1, 38.89103,-90.17013 +/-100m); p18__5 (tier 1, 38.88865,-90.16826 +/-114m); p19__1 (tier 4, 38.89297,-90.17616 +/-2648m); p19__2 (tier 4, 38.89297,-90.17616 +/-2648m); p19__3 (tier 4, 38.89297,-90.17616 +/-2648m); p19__4 (tier 4, 38.89297,-90.17616 +/-2648m); p19__5 (tier 4, 38.89297,-90.17616 +/-2648m)"}],"items":[{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0010/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p10","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0010/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0010","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"27.1,1831.4 17.0,0.0 1613.0,0.0 1613.0,809.3 1416.3,771.5 1196.0,1891.2 690.5,1799.7 27.1,1831.4\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0010/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17645970046489,38.89554949609915]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17255050907812,38.89523527543232]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17302595556774,38.891601306256376]}},{"type":"Feature","properties":{"resourceCoords":[0.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.1769351469545,38.89191552692321]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0011/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p11","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0011/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0011","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"-0.0,-0.0 1613.0,0.0 1613.0,85.7 1569.5,85.6 1576.0,1913.0 30.0,1913.0 30.4,1848.8 -0.0,1849.1 -0.0,-0.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0011/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18032766821813,38.89602503771379]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17628797067414,38.89570561426508]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17677129826265,38.89195039531079]}},{"type":"Feature","properties":{"resourceCoords":[0.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18081099580664,38.8922698187595]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0012/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p12","metadata":[{"label":"streets","value":"6"},{"label":"intersections","value":"9"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0012/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0012","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"260.2,0.0 1613.0,0.0 1613.0,140.3 1241.7,140.3 1240.8,426.8 1613.0,426.4 1613.0,1442.5 1199.8,1437.8 1195.3,1842.0 68.4,1830.9 86.5,131.1 284.4,133.9 260.2,0.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0012/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[637.0,700.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.172301,38.892466]}},{"type":"Feature","properties":{"resourceCoords":[637.0,1271.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.17269,38.891412]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0014__2/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p14 [2]","metadata":[{"label":"streets","value":"4"},{"label":"intersections","value":"4"},{"label":"split_canvas_x","value":"4186.4"},{"label":"split_canvas_y","value":"0.0"},{"label":"split_canvas_w","value":"2265.6"},{"label":"split_canvas_h","value":"2184.4"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0014__2/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0014","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"1613.0,0.0 1047.0,0.0 1046.6,546.1 1185.3,545.6 1613.0,544.3 1613.0,0.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0014__2/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[1102.5,70.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.181076,38.897563]}},{"type":"Feature","properties":{"resourceCoords":[1527.1,70.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.180011,38.897478]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0015/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p15","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0015/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0015","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"385.7,1913.0 383.7,1246.0 -0.0,1249.1 -0.0,955.4 382.8,952.9 382.4,809.1 -0.0,811.6 -0.0,-0.0 1613.0,0.0 1613.0,1913.0 385.7,1913.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0015/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.1698440190473,38.89489783596027]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.16614084225151,38.89404879994758]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.16742551354854,38.89060633329049]}},{"type":"Feature","properties":{"resourceCoords":[0.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17112869034433,38.89145536930318]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0016__2/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p16 [2]","metadata":[{"label":"streets","value":"2"},{"label":"intersections","value":"1"},{"label":"split_canvas_x","value":"3733.6"},{"label":"split_canvas_y","value":"0.0"},{"label":"split_canvas_w","value":"2718.4"},{"label":"split_canvas_h","value":"7652.0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0016__2/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0016","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"1069.0,1913.0 1613.0,1913.0 1613.0,0.0 1145.1,0.0 1143.5,634.3 946.3,648.7 941.7,1089.2 947.9,1913.0 1069.0,1913.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0016__2/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[933.4,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.16279692753054,38.88820775912814]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.16267190062925,38.889532096762764]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.15789039742359,38.88925803411333]}},{"type":"Feature","properties":{"resourceCoords":[933.4,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.15801542432487,38.88793369647871]}},{"type":"Feature","properties":{"resourceCoords":[1119.3,963.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.160355,38.888432]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0016__3/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p16 [3]","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"},{"label":"split_canvas_x","value":"0.0"},{"label":"split_canvas_y","value":"2594.8"},{"label":"split_canvas_w","value":"3785.2"},{"label":"split_canvas_h","value":"2131.2"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0016__3/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0016","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"601.4,869.0 0.0,916.1 0.0,1180.6 940.7,1181.5 946.3,648.7 595.0,656.1 601.4,869.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0016__3/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,648.7],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.15874190406069,38.8882418198526]}},{"type":"Feature","properties":{"resourceCoords":[946.3,648.7],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.157548998149,38.88814419640728]}},{"type":"Feature","properties":{"resourceCoords":[946.3,1181.5],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.15761916760907,38.88761734962503]}},{"type":"Feature","properties":{"resourceCoords":[0.0,1181.5],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.15881207352076,38.88771497307035]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0017__3/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p17 [3]","metadata":[{"label":"streets","value":"6"},{"label":"intersections","value":"8"},{"label":"split_canvas_x","value":"2930.4"},{"label":"split_canvas_y","value":"0.0"},{"label":"split_canvas_w","value":"3521.6"},{"label":"split_canvas_h","value":"7652.0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0017__3/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0017","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"1613.0,1859.8 1613.0,0.0 1091.8,0.0 1093.6,503.3 732.6,834.9 732.7,1688.8 865.0,1835.1 1613.0,1859.8\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0017__3/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[1133.3,1390.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.1868063,38.897163]}},{"type":"Feature","properties":{"resourceCoords":[1365.2,459.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.1860979,38.8988638]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0017__4/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p17 [4]","metadata":[{"label":"streets","value":"4"},{"label":"intersections","value":"6"},{"label":"split_canvas_x","value":"0.0"},{"label":"split_canvas_y","value":"2724.0"},{"label":"split_canvas_w","value":"2930.8"},{"label":"split_canvas_h","value":"4928.0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0017__4/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0017","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"-0.0,1913.0 641.0,1913.0 732.7,1913.0 732.6,834.9 548.4,834.8 307.5,834.8 0.0,681.0 -0.0,1913.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0017__4/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[497.8,1105.7],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.185284,38.902251]}},{"type":"Feature","properties":{"resourceCoords":[497.8,1591.2],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.18527,38.901346]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0018__1/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p18 [1]","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"},{"label":"split_canvas_x","value":"0.0"},{"label":"split_canvas_y","value":"0.0"},{"label":"split_canvas_w","value":"6452.0"},{"label":"split_canvas_h","value":"2649.6"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0018__1/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0018","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"237.2,659.8 1199.6,646.3 1613.0,641.2 1613.0,0.0 201.4,0.0 207.5,613.8 236.9,613.7 237.2,659.8\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0018__1/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.16952294977139,38.88964890427808]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.16570525372899,38.88872499626127]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,662.4],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.16618899582643,38.88749681223671]}},{"type":"Feature","properties":{"resourceCoords":[0.0,662.4],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17000669186883,38.88842072025353]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0018__2/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p18 [2]","metadata":[{"label":"streets","value":"3"},{"label":"intersections","value":"2"},{"label":"split_canvas_x","value":"0.0"},{"label":"split_canvas_y","value":"2585.2"},{"label":"split_canvas_w","value":"4798.8"},{"label":"split_canvas_h","value":"1869.2"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0018__2/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0018","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"103.0,1028.7 1173.7,1028.7 1173.9,980.1 1199.7,980.4 1199.6,646.3 103.0,661.6 103.0,1028.7\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0018__2/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[103.0,1028.7],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.171755,38.890062]}},{"type":"Feature","properties":{"resourceCoords":[1173.7,1028.7],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.169083,38.889439]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0020/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p20","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0020/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0020","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"-0.0,1913.0 -0.0,-0.0 1613.0,0.0 1613.0,1913.0 -0.0,1913.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0020/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.15028227839899,38.90470958661258]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.14636940749467,38.90466147673666]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.14644221486316,38.90102470848267]}},{"type":"Feature","properties":{"resourceCoords":[0.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.15035508576747,38.90107281835859]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0002__1/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p2 [1]","metadata":[{"label":"streets","value":"6"},{"label":"intersections","value":"6"},{"label":"split_canvas_x","value":"0.0"},{"label":"split_canvas_y","value":"0.0"},{"label":"split_canvas_w","value":"6452.0"},{"label":"split_canvas_h","value":"7652.0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0002__1/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0002","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"1098.3,1147.9 1458.2,970.3 1271.2,604.3 1538.2,483.9 1309.5,-0.0 890.4,-0.0 826.2,195.0 250.2,-0.0 -0.0,-0.0 -0.0,1913.0 1231.7,1913.0 1176.1,1751.9 935.0,1270.3 1114.0,1178.8 1098.3,1147.9\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0002__1/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[1238.0,540.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.189119,38.893494]}},{"type":"Feature","properties":{"resourceCoords":[273.0,1638.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.192532,38.892682]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0002__2/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p2 [2]","metadata":[{"label":"streets","value":"2"},{"label":"intersections","value":"1"},{"label":"split_canvas_x","value":"3740.0"},{"label":"split_canvas_y","value":"3796.4"},{"label":"split_canvas_w","value":"2712.0"},{"label":"split_canvas_h","value":"3855.6"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0002__2/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0002","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"1503.3,1498.6 1613.0,1502.5 1613.0,1286.8 1485.3,988.8 935.0,1270.3 1068.8,1537.5 1070.8,1483.2 1190.1,1486.7 1468.7,1592.3 1503.3,1498.6\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0002__2/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[935.0,949.1],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.1902690238365,38.89767855160437]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,949.1],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18731000038645,38.89636828283637]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18969741210832,38.89309490608586]}},{"type":"Feature","properties":{"resourceCoords":[935.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.19265643555838,38.89440517485386]}},{"type":"Feature","properties":{"resourceCoords":[1190.6,1487.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.190487,38.89536]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0003/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p3","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0003/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0003","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"-0.0,1913.0 -0.0,1236.2 111.3,1292.2 396.7,732.8 395.9,590.5 -0.0,591.3 -0.0,397.9 394.9,401.6 393.6,0.0 674.9,0.0 711.9,253.9 1117.9,265.2 1119.6,176.2 1534.0,186.6 1524.2,1565.7 1613.0,1716.8 1613.0,1913.0 -0.0,1913.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0003/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.19010608754127,38.893421759165946]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18611972801695,38.89315753465456]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18651951845375,38.889451765415984]}},{"type":"Feature","properties":{"resourceCoords":[0.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.19050587797807,38.88971598992737]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0004/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p4","metadata":[{"label":"streets","value":"10"},{"label":"intersections","value":"14"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0004/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0004","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"111.5,0.0 606.5,0.0 605.9,49.6 849.3,46.7 849.4,0.0 1613.0,0.0 1613.0,41.0 1473.0,39.0 1472.9,201.7 1473.2,467.2 1613.0,465.8 1613.0,1913.0 -0.0,1913.0 -0.0,1743.3 235.0,1737.3 229.9,1545.8 139.9,1400.6 111.5,0.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0004/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[134.0,910.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.1865434,38.8911115]}},{"type":"Feature","properties":{"resourceCoords":[1473.0,39.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.182893,38.892542]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0005/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p5","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0005/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0005","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"-0.0,1673.0 -0.0,-0.0 116.5,0.0 194.7,58.1 905.9,50.4 903.8,0.0 1613.0,0.0 1613.0,1813.1 1362.4,1816.7 1362.9,1765.9 853.1,1767.2 855.6,1823.1 441.6,1824.2 442.4,1913.0 37.0,1913.0 -0.0,1673.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0005/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18795958322644,38.89652275210072]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18397765121598,38.89617156797348]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18450904051505,38.89247007337742]}},{"type":"Feature","properties":{"resourceCoords":[0.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18849097252551,38.89282125750466]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0006/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p6","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0006/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0006","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"148.6,15.4 1010.3,0.0 1013.4,1672.3 977.5,1673.2 977.2,1826.3 1613.0,1827.2 1613.0,1913.0 282.1,1895.5 288.2,443.9 147.1,445.0 148.6,15.4\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0006/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18326308994425,38.892603922104634]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17920052510752,38.892262223682636]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17971753261482,38.888485565893646]}},{"type":"Feature","properties":{"resourceCoords":[0.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18378009745155,38.888827264315644]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0007/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p7","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0007/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0007","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"31.1,125.7 1588.9,113.6 1588.8,58.4 1613.0,57.0 1613.0,1913.0 -0.0,1913.0 -0.0,1757.8 36.5,1756.8 31.1,125.7\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0007/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18077893161872,38.892515075545504]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17677339496235,38.89217374079103]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17728985159577,38.88845009325417]}},{"type":"Feature","properties":{"resourceCoords":[0.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.18129538825214,38.888791428008645]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0008/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p8","metadata":[{"label":"streets","value":"0"},{"label":"intersections","value":"0"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0008/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0008","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"617.3,91.8 1113.8,135.6 1063.7,685.8 1571.0,733.4 1453.1,1913.0 151.1,1913.0 3.1,177.7 617.3,91.8\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0008/gcps","type":"FeatureCollection","transformation":{"type":"polynomial","options":{"order":1}},"features":[{"type":"Feature","properties":{"resourceCoords":[0.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17671062685864,38.89240721515031]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,0.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17273513975601,38.891797039784414]}},{"type":"Feature","properties":{"resourceCoords":[1613.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.17365836209028,38.88810131244962]}},{"type":"Feature","properties":{"resourceCoords":[0.0,1913.0],"type":"corner"},"geometry":{"type":"Point","coordinates":[-90.1776338491929,38.88871148781551]}}]}},{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0009/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Alton, Illinois | 1902 | sanborn01701_004 p9","metadata":[{"label":"streets","value":"4"},{"label":"intersections","value":"3"}],"created":"2026-09-23T11:17:21Z","modified":"2026-09-23T11:17:21Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0009/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0009","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"-0.0,110.5 1584.0,110.0 1613.0,1913.0 -0.0,1913.0 -0.0,110.5\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd410m:g4104m:g4104am:g017011902:01701_1902-0009/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[554.0,110.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.171755,38.890062]}},{"type":"Feature","properties":{"resourceCoords":[1584.0,110.0],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-90.169083,38.889439]}}]}}]}