Davis Resigns House Seat and Leads the Mississippi Rifles
The year 1846 saw the beginning of the Mexican-American War.
He resigned his House seat in June, and raised a volunteer regiment, the Mississippi Rifles, becoming its colonel. On July 21, 1846 they sailed from New Orleans for the Texas coast. Davis armed the regiment with percussion rifles and trained the regiment in their use, making it particularly effective in combat.
Jefferson Davis, while serving in the Mexican War, became a colonel of Mississippi volunteers and served under his former father-in-law, now General Taylor. At the Battle of Buena Vista, Davis and his regiment probably saved the American army from defeat with Davis' "inspired V-formation" against an overwhelming Mexican force, led by Mexican leader Antonio Lopez de Santa Anna.