Second only to Robert E. Lee on the list of most honored Confederate generals, Thomas Jonathan "Stonewall " Jackson (1824–1863) was born to Jonathan and Julia Jackson in Clarksburg, Virginia (now West Virginia). Orphaned at age seven, Jackson spent most of his youth living with his uncle Cummins Jackson. Despite a background marked by poverty and a lack of formal education, Jackson gained entry to the United States Military Academy at West Point, graduating in 1846 in the top third of his class. After serving with distinction as an artillery officer during the Mexican War, Jackson resigned from the Army in 1852, after becoming a professor of artillery tactics and natural philosophy at the Virginia Military Institute in Lexington, Virginia. When Virginia seceded from the Union at the start of the Civil War in April 1861, Jackson was commissioned as a colonel and charged with transforming volunteer recruits into a cohesive fighting force. On July 21, 1861, his leadership in a dogged defense of the Confederate line at First Manassas (First Bull Run) earned him the nickname "Stonewall." By the end of the year, he had been promoted to major general. Jackson's skills as a leader and strategist came to full fruition in the Shenandoah Valley in Virginia during the spring of 1862. Marching his 17,000 troops rapidly over long distances, he defeated superior Union forces at Front Royal, Winchester, Cross Keys, and Port Republic. Later engagements from 1862 and 1863 that displayed Jackson's tactical genius included the battles of Second Manassas (Second Bull Run), Harpers Ferry, Sharpsburg (Antietam), and Fredericksburg. Jackson was seriously wounded by friendly fire on May 2 while again distinguishing himself during Lee's stunning victory at Chancellorsville. A deeply religious man, Jackson's last words before dying of pneumonia on May 10, 1863, were "Let us cross over the river and rest under the shade of the trees. "