Union general (1815–1874), known as “Old Brains,” who, despite his administrative skill as general in chief, failed to achieve an overall battle strategy for Union forces. Lincoln once described him as “little more than a first rate clerk.” Ink signature, “H. W. Halleck, U.S. Chief of Staff, March 17th, 1864,” on an off-white 5.5 x 2.5 slip. In very fine, clean condition. R&R COA.