The Union Army of the Tennessee, commanded by Major General Ulysses S. Grant, who later became president captured the fort in February 1862 from the Confederate Army in the Battle of Fort Donelson. This was a great strategic victory for the Union forces, and part of Grant's campaign to gain control of the Mississippi River. Union forces occupied the fort (and much of Tennessee) for the remainder of the war. A small detachment of Confederate troops made one unsuccessful attempt in 1863 to regain it.