1815–72, Union general in the American Civil War, b. Oneida co., N.Y., grad. West Point, 1839. He entered the Corps of Engineers and became an expert on fortifications; his Elements of Military Art and Science (1846) was influential in the Civil War. In the Mexican War he served in California, holding various positions in the military government there. Halleck resigned from the army in 1853 and entered the leading law firm of the state. In the Civil War he was made a major general in the regular army (Aug., 1861) and was sent to succeed John C. Frémont in command of the Dept. of the Missouri. In Mar., 1862, the departments of the Ohio and Kansas were added to his jurisdiction. Although he was an able organizer, the prestige that he gained was due to the successes of Ulysses S. Grant, Don Carlos Buell, Samuel R. Curtis, and John Pope—all under his command. After Shiloh (Apr., 1862) Halleck took the field himself and advanced on Corinth, which General Beauregard abandoned to him in May. In July, 1862, he was appointed general in chief with the understanding that he was to remain in Washington as military adviser to the President and the Secretary of War. His failure to act decisively made him ineffective as general in chief, however, and he was grateful when, upon Grant's being given supreme command in Mar., 1864, he was demoted to chief of staff. He remained in the army after the war and held command of the Division of the South at the time of his death.
Summary Article: Halleck, Henry Wager
From The Columbia Encyclopedia