Thomas Jonathan Jackson was born on January 21, 1824 at Clarksburg, Virginia(which is now West Virginia). His father, Jonathan Jackson was an attorney(1790-1826). His mother was Julia Beckwith Neale(1790-1831). He had an older brother, Warren Jackson(1821-1841), an older sister Elizabeth(1819-1826), and a younger sister Laura Ann(1826-1911). Both his father and younger sister died of typhoid fever. Jackson's mother died of childbirth complications December 4, 1831. His mother remarried to Blake Woodson. Thomas and Laura went to live with their uncle, Cummins Jackson, after their brother Warren died in 1841 of tuberculosis. .

             Starting in June of 1842, Jackson was schooled at the United States Military Academy at West Point. He graduated in June of 1846. He was ranked 17th out of the 59 graduates. He began his career as a 2nd Lt., First Artillery Regiment in the United States Army. Jackson served in the Mexican War from 1846-1848 and was stationed at Carlisle Barracks, Pennsylvania; Fort Hamilton, New York; and Fort Meade, Florida. In early 1851, Jackson began his teaching career at the Virginia Military Institute in Lexington, Virginia. At the same time, he had resigned from the army. At VMI, Jackson taught natural and experimental philosophy. .

             Two years later on August 4, 1853, Jackson married Elinor Junkin. Sadly, on October 22, 1854, Elinor died in childbirth. Their son was stillborn. On July 16, 1857, Jackson had remarried to Mary Anna Morrison. Together, they had two daughters. One, Mary Graham Jackson, died after only one month. The other, Julia Laura Jackson, was born in November of 1862 and died of typhoid fever in 1889. .

             In November of 1859, Jackson was a VMI officer who accompanied VMI cadets to Harper's Ferry at the hanging of abolitionist John Brown. On April 27, 1861, shortly after the beginning of the Civil War, a promoted Col. Jackson took command at Harper's Ferry.