Potomac River (in four sheets): Sheet no. 4, from Indian Head to Georgetown
Scale 1:40,000. LC Civil War Maps (2nd ed.), 53.4 "No. 391" in upper left corner of map. "Electrotype copy no. 1, by G. Mathiot, U.S.C.S." is printed in the upper margin. Information concerning lighthouses, tides, soundings, and the geographic coordinates of the Capitol dome is given in the lower right corner. Description derived from published bibliography. Available also through the Library of Congress web...
Harrison, A. M. (Alexander Medina) - United States Coast Survey - Bache, A. D. (Alexander Dallas)