1864 Potomac River

Potomac River (in four sheets): Sheet no. 4, from Indian Head to Georgetown From a trigonometrical survey under the direction of A. D. Bache, Superintendent of the survey of the coast of the United States. Triangulation by A. D. Bache, Supdt., C. Ferguson, C. Hosmer and C. H. Boyd, Sub-Assts. Topography by A. M. Harrison, C. M. Bache, Assts., J. Mechan, C. Hosmer and C. H. Boyd, Sub-Assts. Hydrography by the parties under the command of Lieut. comdr. T. S. Phelps, U.S.N. and C. P. Patterson Assi