Stonewall Jackson had a complex military career. Jackson was involved with five separate military organizations. He began his career at the age of 18 when he entered the United States Military Academy. While attending the academy, Jackson quickly climbed the ranks. On July 1, 1846 he graduated the academy with the rank of Brevet Second Lieutenant.

On July 22, 1946, Jackson began his official military career. He was assigned Company K of the 1st U.S. Artillery. However, he did not immediately enter battle. Instead, he was assigned to recruiting duty. On August 19, 1946, Jackson entered combat in the Mexican-American War. During the Mexican-American War, he participated in the Siege of Veracruz and the Battle of Cerro Gordo. In April of 1947, Jackson became a Second Lieutenant in the United States Army. By the end of the Mexican-American War, Jackson had climbed to First Lieutenant.

After the Mexican-American War, Jackson became disgruntled with the United states Army. In 1851, he resigned from all military duties. He pursued a career as a instructor at the Virginia Military Institute. During the Civil War, Jackson became a Colonel in the Confederates Army. He was in charge of the entire Virginia Militia. On October 31, 1861, Jackson joined the Confederate States Army as a Major of Artillery.