Henry Wager Halleck, b. Jan. 16, 1815, d. Jan. 9, 1872, was a Union general during the American Civil War. After graduating from West Point in 1839, he studied military institutions in Europe. His Elements of Military Art and Science (1846) was used as a textbook during the Civil War. During the Mexican War, he saw limited service in California, where he helped draw up the state constitution and later practiced law.
Halleck was named a Major General when the Civil War began. As a harsh, rude theater commander in the Mississippi valley, he demonstrated administrative ability though neither tactical nor strategic skill. In July, 1862, he became General in Chief of the Union armies, an onerous position in which he was ineffective. Replaced by Gen. Ulysses S. Grant in early 1864, Halleck then served as Chief of Staff in Washington, D.C. After the war he headed several military departments.
Bibliography: Ambrose, Stephen E., Halleck, Lincoln's Chief of Staff (1962).