Army of Mississippi in the context of "Battle of Shiloh"

The siege of Vicksburg (May 18 – July 4, 1863) was the final major military action in the Vicksburg campaign of the American Civil War. In a series of maneuvers, Union Major General Ulysses S. Grant and his Army of the Tennessee crossed the Mississippi River and drove the Confederate Army of Mississippi, led by Lieutenant General John C. Pemberton, into the defensive lines surrounding the fortress city of Vicksburg, Mississippi, leading to the successful siege and Confederate surrender.

Vicksburg was the last major Confederate stronghold on the Mississippi River; therefore, capturing it completed the second part of the Northern strategy, the Anaconda Plan. When two major assaults against the Confederate fortifications, on May 19 and 22, were repulsed with heavy casualties, Grant decided to besiege the city beginning on May 25. After holding out for more than 40 days, with their supplies nearly gone, the garrison surrendered on July 4. The Vicksburg campaign's successful ending significantly degraded the Confederacy's ability to maintain its war effort. This action, combined with a siege that led to the surrender of the downriver Port Hudson to Major General Nathaniel P. Banks on July 9, yielded command of the Mississippi River to the Union forces, that held it for the rest of the conflict.

Braxton Bragg (March 22, 1817 – September 27, 1876) was an American military officer during the Second Seminole War and Mexican–American War. He later served as a Confederate general in the American Civil War, seeing action in the Western Theater. His most important role was the commander of the Army of Mississippi, later renamed the Army of Tennessee, from June 1862 until December 1863.

Bragg, a native of Warrenton, North Carolina, was educated at West Point and became an artillery officer. He served in Florida and then received three brevet promotions for distinguished service in the Mexican–American War, most notably the Battle of Buena Vista. He resigned from the U.S. Army in 1856 to become a sugar plantation owner in Louisiana. At the start of the Civil War, Bragg trained soldiers in the Gulf Coast region. He was a corps commander at the Battle of Shiloh, where he launched several costly and unsuccessful frontal assaults but nonetheless was commended for his conduct and bravery.