A Civil War general and Indian fighter, Custer (1839–1876) distinguished himself as a cavalry commander, earning the rank of brigadier general of volunteers at age 23. Following the Civil War he became field commander of the 7th Cavalry and led troops in a number of engagements during the Indian Wars. Custer, together with all of the men under his immediate command, was killed at the Battle of Little Bighorn on June 25, 1876. ALS signed “G. A. Custer,” one page, 5 x 8, March 28, 1866. Custer, then en route to a meeting with Secretary of War Stanton and a party for Chief Justice Chase, writes from the Fifth Avenue Hotel to Mr. [John B.] Batchelder. In full: “I will not be able to keep my engagement with you tomorrow. I will call however at my earliest convenience, not later than next Tuesday morning….” John B. Batchelder (1825–1894) was a colonel, teacher, historian, cartographer, and artist with a special interest in the Battle of Gettysburg; in 1880 he was granted an unusual and generous appropriation by Congress to produce the official history of the battle. The meeting with Custer was possibly related to a portrait sitting. Very faint toning along intersecting mailing fold (vertical fold to “G”) and a few mild wrinkles and subtle blots, otherwise fine, bright condition. Auction LOA John Reznikoff/PSA/DNA and R&R COA.