American Civil War Union Brigadier General. His father was a lawyer who provided him with his early education. In 1849 he received an appointment to the US Military Academy at West Point, New York and graduated in 1853 as a brevet 2nd lieutenant in US Army Ordinance. His first assignment was with the Watervliet Arsenal in Troy, New York and in 1855 he was assigned bask to West Point as an Assistant Professor of Geography, History, and Ethics. In 1857 he became an ordinance officer at the Pittsburgh, Pennsylvania Arsenal and the following year he was sent to Vancouver in Washington Territory to oversee the building of an arsenal, but difficulties with the British Government prevented it and he was reassigned to Watervliet Arsenal. A few months later he was ordered to Fort Leavenworth, Kansas but resigned his commission in January 1861 and taught mathematics and civil engineering in the Brooklyn Collegiate and Polytechnic Institute (now New York University Polytechnic School of Engineering) in Brooklyn, New York City, New York. After the outbreak of the American Civil War in April 1861 he resigned his teaching post and offered his services to the Governor of Ohio, who appointed him Assistant Adjutant General of the State in May 1861 and he began the organization of the Ohio forces in the Union Army. In August 1861 he was commissioned colonel of the 33rd Ohio Infantry and accompanied Brigadier General William "Bull" Nelson in the Eastern Kentucky expedition and saw combat at the Battle of Ivy Mountain. He then became a brigade commander in Brigadier General Ormsby M. Mitchel's division of the Army of the Ohio and was promoted to the rank of brigadier general in July 1862. Shortly thereafter he was elevated to command of a division but was soon reassigned to command a brigade in Major General Philip Sheridan's division of the Army of the Cumberland. On December 31, 1862 he participated in the bloodiest battle of the Civil War (in terms of percentage of casualties on both sides), the Battle of Stones River, just outside of Murfreesboro, Tennessee. On the eve of the battle, he had been in conference with his commander, General Sheridan and when the conference adjourned and the attendees began to disperse, he and Sheridan mistakenly put on each other's coats. On the first day of the fight, he was killed by rifle fire at the age of 31 while leading his men to battle. His body was found by Confederate troops, who buried it in a battlefield cemetery near the scene of his death until it was later moved to its current burial location. In 1869 General Sheridan, officially established a military post in the Wichita Mountains of Oklahoma and named it Fort Sill in his honor