Sanborn Maps (Library of Congress) This link opens in a new window
This collection consists of large-scale fire insurance maps published by the Sanborn Map Company and digitized by the Library of Congress. The maps depict the commercial, industrial, and residential sections of some twelve thousand cities and towns in the United States, Canada, and Mexico. An extensive collection of Sanborn maps for Wisconsin communities is also available from the Wisconsin Historical Society; click here
to view that collection. Coverage: 1867-1970.