Description: We try to have historical data on all of the city's street-facing and addressed buildings, along with significant campus buildings and historical accessory and alley buildings. Right now there 131,597 buildings included here. These are not house histories, just a modicum of data regarding the building's provenance. About 3/4 of the building features here include data from the DC Historical Building Permits Database (1872-1958). Other sources of data include DCGIS-issued building permits and footprints (2012-present), Google Streetview (2008-present), DCGIS-issued orthophotos (1995-present), DCOS's SurDocs sytem (1920-present), newspaper reports, tax records, period real estate maps, city directories, etc.