Sources & method
Every property in the Atlas is cross-referenced to public records. Histories, dates, and photographs are drawn from the primary archives below, each citable one link away.
- 01 National Register of Historic Places (NRHP) ↗ U.S. National Park Service
Authoritative property listings — Ref # plus location, period, area of significance, and the original nomination form for every entry where one is available.
- 02 Historic American Buildings Survey (HABS) ↗ U.S. Library of Congress
Measured drawings and large-format documentary photography. Most of the black-and-white plate images in the catalog originate here.
- 03 Carol M. Highsmith Archive ↗ U.S. Library of Congress · Prints & Photographs Division
Public-domain colour photography of historic buildings across the U.S., released to the LoC without restriction by the photographer.
- 04 Wikimedia Commons & Wikipedia ↗ Wikimedia Foundation
Community photography under CC-BY-SA; Wikipedia article text is used only for cross-reference and never copied verbatim.
- 05 NPGallery ↗ U.S. National Park Service
Searchable NPS image archive — supplements HABS for properties inside National Parks, Monuments, and Memorials.
- 06 State Historic Preservation Offices ↗ National Conference of State Historic Preservation Officers
Each state's SHPO publishes its own register, often with entries that pre-date or supplement the federal NRHP listing.
Method
Property records are aggregated from the registries above, deduplicated by NRHP ref or canonical slug, normalised against a single schema, and validated before publication. Photographs are migrated to a Cloudflare R2 content delivery network and credited per-entry to their archive of origin. History prose is drafted from primary records and reviewed against the cited sources; where coverage is thin, the entry says so plainly.
Corrections
Errors of fact, missing citations, and additional documented properties are welcomed — reach the editors via the contact link in the footer.