Map of the battle field of Gettysburg, July 1st, 2nd, 3rd 1863. ; Second day's battle.Bachelder, John B. (John Badger), 1825-18941876"Positions of troops compiled and added for the government by John B. Bachelder.""The survey was ordered by Brevet Major General A.A. Humphreys, Chief of Engineers, and conducted under Brevet Major General G.K. Warren, Major of Engineers."Relief shown bcartographic