Constructed in 1867, this building served as the private quarters for commanding officers and their families while stationed here. The 13th U.S. Infantry occupied it from 1867 to 1871, including Maj. William Clinton, Lt. Col. G.L. Andrews, Col. I.V.D. Reeves, and Gen. Phillip R. De Trobriand. The 7th U.S. Infantry used it from 1872 to 1879, including Gen. John Gibbon. The 3rd U.S. Infantry occupied it from 1878 to 1888, including Col. John F. Brooke and Lt. Col. George Gibsin. The 25th U.S. Infantry used it from 1888 to 1891, including Lt. Col. James J. Van Horn and Lt. Col. J.K. Andrews.