Henry Wager Halleck was born in Westernville, Oneida County, New York, on 16 January 1815; was educated at Hudson Academy, received the bachelor of arts degree from Union College, and graduated from the United States Military Academy in 1839; was commissioned in engineers and assigned to work on New York harbor fortifications; visited Europe and wrote a report on French fortifications that was published by the Congress as an official document, 1844; delivered a series of twelve lectures before the Lowell Institute of Boston, published in 1846 under the title Elements of Military Art and Science; while en route by sea to Mexican War service in California, translated Henri Jomini?s Vie politique et militaire de Napol?on, 1846; participated in military operations in Mexico and Lower California and held staff positions, including that of secretary of state of California, in the military government under Generals Richard B. Mason and Bennet Riley, 1847?1849; was brevetted captain for gallant conduct and meritorious service, May 1847; was aide to General Riley, 1850, and a member of an engineer board for Pacific Coast fortifications, 1853?1854; resigned from the Army to pursue private interests, August 1854; married Elizabeth Hamilton, 1855; entered the practice of law as head of the firm of Halleck, Peachy and Billings, 1853?1854; was president of the Pacific and Atlantic Railroad, 1855, and director of the New Almaden Quicksilver Mine, 1853?1861; was major general of California militia, 1860?1861; published treatises on mining and international law; was reappointed major general in the Regular Army, August 1861; commanded the Department of the Missouri, 1861?1862, and the Department of the Mississippi, 1862; commanded the Union forces in the Corinth operations; was commanding general of the United States Army, 23 July 1862?9 March 1864; was an influential champion of discipline; published his Jomini translation in four volumes; was reassigned as chief of staff of the Army, 12 March 1864?19 April 1865; commanded the Division of the James, April?July 1865; commanded the Division of the Pacific, 1865?1869; commanded the Division of the South, 1869?1872; died at his headquarters in Louisville, Kentucky, on 9 January 1872.