After the
Battle of Shiloh, the Thirteenth Iowa was assigned to the Third Brigade of the Sixth Division. The Brigade was composed of the Eleventh,
Thirteenth,
Fifteenth and
Sixteenth regiments of Iowa Infantry, and was under command of
Colonel Crocker. This organization remained intact until the close of the war. Except when upon detached duty, the operations of each of the regiments were identified very largely with those of the brigade, and, therefore, the history of each of these four Iowa regiments is almost inseparably interwoven with that of the brigade. File:20-13-103-vicksburg.jpg|Relief portrait of Col. William Hall at
Vicksburg National Military Park File:Crockers Brigade.jpg == References==