Cadastral Map

A Cadastral Map is a map that shows the boundaries and ownership of land parcels. Some cadastral maps show additional details which contains district names, and certain identification numbers for parcels.  This particular cadastral map is of the city of Washington in 1792, showing land tracks and the town sites of  Georgetown, Hamburgh, and Carrollsburg.
http://www.terrain.org/columns/23/savoy.htm