Thomas Jonathan Jackson was born on January 21, 1824 in Clarksburg, Virginia. He entered West Point in July 1842 and, in spite of his poor childhood education, worked hard to graduate seventeenth in his class in 1846. Upon graduation, Jackson was sent on military duty to Mexico, and continued his service in the United States Army in positions in New York and Florida. In 1851, Jackson became professor of artillery tactics and natural philosophy at Virginia Military Institute in Lexington, Virginia. He resigned from the army as of February 29, 1852.
sources: Dictionary of American Biography
Jackson at VMI