Run v1.3
Georeferencing for the Library of Congress's Sanborn Maps Collection, made automatically by mapsnap: each placed sheet is a IIIF Georeference Annotation you can open in Allmaps or any viewer that reads them.
Try one
Brooklyn, Kings County, New York, vol. 2, 1939
opens in the Allmaps viewer: 63 georeferenced sheets over today's map, drawn from Chronoscope's copies of the scans. The file behind it is
https://data.mapsnap.org/runs/v1.3/iiif/chronoscope/sanborn05791_054.main.iiif.json.
Download
| mapsnap-v1.3-loc.zip | Every IIIF file, pointing at loc.gov, with items.tsv and README.txt | 99 MB |
| mapsnap-v1.3-chronoscope.zip | Every IIIF file, pointing at Chronoscope, with items.tsv and README.txt | 98 MB |
| items.tsv | One row per volume, published or not | 6 MB |
The files
Each published volume has a IIIF AnnotationPage of its main content, <item>.main.iiif.json, and of its key map when one was placed, <item>.keymap.iiif.json. Every file comes in two versions that differ only in where the scans are fetched from:
https://data.mapsnap.org/runs/v1.3/iiif/loc/points at the Library of Congress's own image servers, the original scans.https://data.mapsnap.org/runs/v1.3/iiif/chronoscope/points at Chronoscope's copies of the same scans at a quarter of their size, which load much faster and are kinder to loc.gov.
Each file's id is its own URL. Every image is a georeference annotation: control points, a transformation, and a clip outline for the part of the sheet that is map.
Limitations
mapsnap can't place every page, and not every page it places is accurate: a sheet can land on the wrong block, or in the wrong town. If you find a volume that's wrong, please report it on GitHub.
OldInsuranceMaps.net
mapsnap was built with data from OldInsuranceMaps.net, where volunteers have georeferenced Sanborn maps by hand; their work is what mapsnap was developed and measured against. If a volume you want isn't listed here, or is missing pages, look for it on OldInsuranceMaps.net, or georeference it by hand there.
States
| State | Volumes published | of | Sheets placed | of | % |
|---|---|---|---|---|---|
| Alabama | 378 | 452 | 4,027 | 5,768 | 70% |
| Alaska | 9 | 18 | 22 | 63 | 35% |
| Arizona | 136 | 197 | 1,408 | 1,948 | 72% |
| Arkansas | 467 | 571 | 3,572 | 4,556 | 78% |
| California | 1,279 | 1,715 | 23,762 | 29,928 | 79% |
| Colorado | 450 | 519 | 3,096 | 4,062 | 76% |
| Connecticut | 341 | 461 | 5,513 | 7,417 | 74% |
| Delaware | 91 | 95 | 492 | 620 | 79% |
| District of Columbia | 6 | 9 | 369 | 692 | 53% |
| Florida | 362 | 429 | 3,839 | 5,341 | 72% |
| Georgia | 512 | 592 | 4,076 | 5,437 | 75% |
| Hawaii | 21 | 39 | 1,015 | 1,355 | 75% |
| Idaho | 273 | 395 | 1,773 | 2,431 | 73% |
| Illinois | 1,717 | 1,882 | 22,571 | 26,685 | 85% |
| Indiana | 1,191 | 1,261 | 13,110 | 15,238 | 86% |
| Iowa | 991 | 1,178 | 6,772 | 8,865 | 76% |
| Kansas | 849 | 964 | 5,621 | 6,938 | 81% |
| Kentucky | 468 | 569 | 4,707 | 6,238 | 75% |
| Louisiana | 384 | 429 | 5,118 | 6,353 | 81% |
| Maine | 407 | 594 | 2,798 | 3,851 | 73% |
| Maryland | 277 | 321 | 5,733 | 7,250 | 79% |
| Massachusetts | 886 | 1,012 | 15,633 | 19,712 | 79% |
| Michigan | 1,275 | 1,370 | 13,191 | 16,635 | 79% |
| Minnesota | 620 | 854 | 6,973 | 9,932 | 70% |
| Mississippi | 396 | 455 | 2,370 | 3,076 | 77% |
| Missouri | 1,061 | 1,150 | 9,379 | 11,047 | 85% |
| Montana | 344 | 481 | 2,682 | 3,508 | 76% |
| Nebraska | 396 | 524 | 2,393 | 3,291 | 73% |
| Nevada | 70 | 81 | 504 | 623 | 81% |
| New Hampshire | 269 | 358 | 2,198 | 2,957 | 74% |
| New Jersey | 781 | 862 | 14,235 | 18,589 | 77% |
| New Mexico | 125 | 153 | 1,062 | 1,398 | 76% |
| New York | 2,114 | 2,517 | 31,394 | 43,609 | 72% |
| North Carolina | 496 | 553 | 5,021 | 6,705 | 75% |
| North Dakota | 168 | 224 | 1,035 | 1,461 | 71% |
| Ohio | 1,660 | 1,749 | 24,735 | 30,804 | 80% |
| Oklahoma | 922 | 1,191 | 5,556 | 7,272 | 76% |
| Oregon | 432 | 582 | 3,572 | 4,883 | 73% |
| Pennsylvania | 1,836 | 2,025 | 22,637 | 28,782 | 79% |
| Rhode Island | 107 | 129 | 3,328 | 4,322 | 77% |
| South Carolina | 325 | 376 | 2,488 | 3,301 | 75% |
| South Dakota | 352 | 425 | 1,220 | 1,672 | 73% |
| Tennessee | 457 | 542 | 7,938 | 10,037 | 79% |
| Texas | 1,397 | 1,597 | 15,630 | 19,437 | 80% |
| Utah | 42 | 164 | 1,395 | 2,563 | 54% |
| Vermont | 252 | 321 | 1,551 | 2,247 | 69% |
| Virginia | 438 | 488 | 5,993 | 8,090 | 74% |
| Washington | 630 | 805 | 7,787 | 9,740 | 80% |
| West Virginia | 268 | 295 | 2,639 | 3,573 | 74% |
| Wisconsin | 848 | 977 | 6,480 | 8,645 | 75% |
| Wyoming | 97 | 126 | 680 | 938 | 72% |
items.tsv
item | The Library of Congress item id; its page is https://www.loc.gov/item/<item>/. |
city, state, year, date | The town, its postal code, and the volume's year and catalogue date. |
volume | The volume number, where the catalogue gives one. |
title | The catalogue title. |
sheets | Scanned sheets in the volume. |
images | Images the run split the sheets into (split sheets become several). |
placed | Images the run georeferenced. |
published | Images published: those placed, less the ones dropped below. |
sheets_placed | Sheets with at least one published image. |
dropped_over_6km | Images dropped because their sheet would span over 6 km of ground. |
dropped_over_5km_from_location | Images dropped because, in a volume of 10 sheets or fewer, they sit over 5 km from the catalogue's location for the town. |
status | published, no page placed, or withheld and why. |
main, keymap | The volume's IIIF file names, under iiif/loc/ and iiif/chronoscope/; blank if none. |
License
The georeferencing annotations are © OpenStreetMap contributors and mapsnap, available under the Open Database License 1.0: their control points are OpenStreetMap positions. Individual contents are under the Database Contents License. The sheet images are the Library of Congress's Sanborn Maps Collection.