Thomas Jonathan 'Stonewall' Jackson was the great-grandson of indentured servants from Ireland who were sentenced to serve time in America for larceny. He began his career in the U.S. Army fighting in the Mexican-American War and later became a teacher. He and his wife owned slaves, and he saw slavery as ordained by God, although he also considered it the slave master's duty to treat servants fairly and humanely at all times. His reputation as a kind slave master meant several slaves asked to be purchased by him at auction. Called to serve in the Civil War in 1861, he excelled during several battles including the First Battle of Bull Run, where he got his nickname, and became one of the most revered Confederate commanders. To this day, his Valley Campaign of 1862 is studied worldwide as an example of innovation and bold leadership. Historians consider Stonewall Jackson to be one of the most gifted tactical commanders in United States history.