SLOCUM, HENRY WARNER, an American military officer; born in Delphi, Onondaga co., N. Y., Sept. 24, 1827. He was graduated at the United States Military Academy in 1852; resigned his commission in 1856; studied law, and practiced in Syracuse, N. Y. He was elected a member of the State Legislature in 1859. When the Civil War broke out he was commissioned a colonel of volunteers in the Union army. He was at the first battle of Bull Run, commanding a regiment, July 21, 1861; was promoted Brigadier-General in the autumn of 1861, and commanded a division in the battles of Gaines's Mill, White Oak Swamp, and Malvern Hill. In 1862 he was promoted Major-General; participated in the battles of Bull Run, Aug. 29 and 30; commanded a corps at the battle of Chancellorsville, and at Gettysburg, July 2 and 3, 1863, was placed in command of a corps on the left wing of General Sherman's army; and took part in the great “March to the Sea,” leading the left wing of the army from Atlanta to Savannah. In September, 1865, he resigned from the army; settled in Brooklyn; and resumed the practice of law. He was elected to Congress in 1869 and served till 1873. He died in Brooklyn, N. Y., April 14, 1894.