This is a beautiful topographical map of the area that would become Rock Creek Park. The map was done in 1866 in compliance with a Senate Resolution of July 18th, 1866.
Topographical sketch of the environs of Washington, D.C. : (survey of locality for public park & site for a presidential mansion) / to accompany report of N. Michler, Major of Eng’rs, Bvt. Brig. Gen’l U.S.A.