Union general and secretary of war (1829–1890) who holds the distinction of being the only Cabinet secretary ever to have been impeached. Fountain pen signature, “Wm. W. Belknap, Sec’y of War, Feb. 14, 1870,” on an off-white 4.5 x 2.5 slip. In fine condition, with irregularly trimmed edges and a mounting remnant lightly showing through from the back. RRAuction COA.