Irvin McDowell (October 15, 1818 – May 4, 1885) was a career American army officer. He is best known for his defeat in the First Battle of Bull Run, the first large-scale battle of the American Civil War. In 1862, he was given command of the I Corps of the Army of the Potomac. He fought unsuccessfully against Thomas "Stonewall" Jackson's troops during the Valley Campaign of 1862, and was blamed for contributing to the defeat of United States troops at the Second Battle of Bull Run in August. Early life McDowell was born in Columbus, Ohio, son of Abram Irvin McDowell and Eliza Seldon McDowell. He was a cousin-in-law of John Buford, and his brother, John Adair McDowell, served as the first colonel of the 6th Iowa Volunteer Infantry Regiment during the Civil War. McDowell initially attended the College de Troyes in France before graduating from the United States Military Academy in 1838, where one of his classmates was P. G. T. Beauregard, his future adversary at First Bull Run. He was commissioned a second lieutenant and posted to the 1st U.S. Artillery. McDowell served as a tactics instructor at West Point, before becoming aide-de-camp to General John E. Wool during the Mexican–American War. He was brevetted captain at Buena Vista and served in the Adjutant General's department after the war. While in that department he was promoted to major on May 31, 1856. Between 1848 and 1861, McDowell generally served as a staff officer to higher-ranking military leaders, and developed experience in logistics and supply. He developed a close friendship with General Winfield Scott while serving on his staff. He also served under future Confederate general Joseph E. Johnston. Civil War McDowell was promoted to brigadier general in the regular army on May 14, 1861, and was given command of the Army of Northeastern Virginia on May 27. The promotion was partly because of the influence of his mentor, Treasury Secretary Salmon P. Chase. Although McDowell knew that his troops were inexperienced and unready, and protested that he was a supply officer, not a field commander, pressure from the Washington politicians forced him to launch a premature offensive against Confederate forces in Northern Virginia. His strategy during the First Battle of Bull Run was imaginative but ambitiously complex, and his troops were not experienced enough to carry it out effectively, resulting in an embarrassing rout. After the defeat