Union officer who commanded a brigade in the IX Corps of the Army of the Potomac at several important battles, including the Battle of Antietam (1824–1869). Civil War–dated LS signed “B. C. Christ, Late Col. 50th Rgt. PVV,” one page, lightly-lined, 7.25 x 9, City Point, Virginia, September 30, 1864. Letter to the provost marshal on the day he was mustered out of the Union army. In full: “I have the honor to ask permission to take one horse to Washington, D. C. Said horse is my own property, purchased outside the lines of the Army, and was never the property of the United States.” Affixed to reverse is a partly-printed slip approving the request. Professionally inlaid into a slightly larger sheet. In fine condition, with scattered creases and light soiling. This is the first item we have offered from this Union officer. RR Auction COA.