Best known for his heroics on Big and Little Round Tops at Gettysburg, Warren served as Harney’s Topographical Engineer during the First Sioux War, and in 1857 he led the first military expedition into the Black Hills. Precise ink signature, “G. K. Warren, Maj. Genl. Vols,” on an off-white 3.5 x 2.25 card. In very fine condition. R&R COA.