Gen. Heintzelman and staff, Harrison's Landing, Aug., 1862

Samuel Peter Heintzelman (September 30, 1805-May 1, 1880) General in the Union Army during the U.S. Civil War who commanded the III Corps of the Army of the Potomac during in the Peninsula Campaign. In 1862, he was assigned to the defense of Washington, D.C. in command of the Department of Washington. For the remainder of the war he commanded the Northern Department.