Written on the photograph is "Maj. Gen. Halleck Com. in-chief U.S.A." The handwriting is probably that of Maj. Abner R. Small, adjutant of the 16th Maine volunteer infantry.

Henry W. Halleck (1815-1872), a native of New York and graduate of the U.S. Military Academy, became major general for the U.S. in August 1861. He often was criticized for being slow to move his forces, thus allowing the Confederates to retreat or gain an advantage.

He served as President Abraham Lincoln's chief of staff from March 1864 to April 1865.