Gaps and Silences in Archives and Special Collections
While archives have been viewed as unbiased repositories of the past in its entirety, they are in fact spaces of gaps and silences. These gaps and silences are due to changing opinions of archivists have considered "of enduring value," and can reflect historical, institutional, and internalized racism, classism, sexism, and ignorance of marginalized genders and sexualities. Biases may also impact the archivist's description. Archives are not neutral.
Sanborn Fire Insurance Maps are a valuable resource for local history. The Sanborn Map Company was a publisher of detailed maps of U.S. cities and towns in the 19th and 20th centuries. The maps were originally created to allow fire insurance companies to assess their total liability in urbanized areas of the U.S. Since they contain detailed information about properties and individual buildings, Sanborn maps are invaluable for documenting the changes in the built environment of American cities over many decades.
Cal Poly holds a subscription to digital access of California Sanborn Maps. The maps are in black and white. Access remotely with a Cal Poly account or on library computers/using campus wifi on your own laptop.
The Library of Congress provides access to digitized Sanborn Maps in color. They are continuing to add more maps. To find SLO County maps, search for the town or search for "San Luis Obispo" to find all county maps.
1886 Sanborn Map of San Luis Obispo, Library of Congress Geography and Map Division
Interactive San Luis Obispo City Sanborn Mapping Projects:
Finding aid for the historical building permit records within the City of San Luis Obispo. Select building permits for the City of San Luis Obispo, California for years 1906-1937 with yearly alphabetical indices for 1923 and 1928-1937. The permits are not a complete issue.
View and download USGS historic topo quads for areas throughout the US. Less detailed, but more comprehensive in extent than the Sanborn maps, USGS topo quads are generally available from 1890-present.
The Library of Congress is the nation's oldest federal cultural institution and serves as the research arm of Congress. It is also the largest library in the world, with millions of books, recordings, photographs, maps and manuscripts in its collections.
A historical map collection containing tens of thousands maps and images online. The collection focuses on rare 18th and 19th century North American and South American maps and other cartographic materials. Historic maps of the World, Europe, Asia, and Africa are also included.
The American Geographical Society Library Digital Map Collection currently contains over 700 maps, ranging from early maps of Asia to historical maps of Wisconsin and Milwaukee, and other American cities, states, and national parks. The digital collection is under continuing development.