Union general who commanded the Cavalry Corps of the Army of the Potomac during the Gettysburg Campaign, including the largest predominantly cavalry battle of the war, Brandy Station. In 1864 he defeated Confederate General Sterling Price in two key battles, effectively ending the war in Missouri. War-dated ALS signed “A. Pleasonton, Maj. Genl,” one page, lightly-lined, 7.75 x 6.75, April 4, 1864. Short letter to the editor of the Army and Navy Journal. In full: “Please address A. & N. Journal to me at this place (St. Louis, Mo.) for the remainder of my term of subscription.” In very good condition, with intersecting folds, one through a single letter of signature, scattered creases, hole to center of page, rough bottom edge, and several notations. Pre-certified PSA/DNA and RRAuction COA.