The Library of Congress continues to digitize its Sanborn fire insurance maps for various communities across America. These maps begin in the 1800s onward to (more or less) the present day. They are invaluable to local history researchers, because they identify locations of local businesses and houses at various times in a town's history.
Browse the LOC Sanborn maps online, and for additional Indiana-specific Sanborn maps, visit the Indiana Spatial Data Portal.
If you're interested in Sanborn maps specifically for Mooresville, Indiana, we have CD-ROM discs (with PDF files of the maps) available to checkout from Mooresville Public Library's Evergreen Indiana catalog. Digitized versions are also available on MPL's website.