After the declaration of war, General Order 36 of May 7, 1898 approved the organization of eight "army corps," each of which was to consist of three or more divisions of three brigades each.

The brigade staff was identical except that no inspector general or ordnance officer was authorized.

General Order 46 of May 16, 1898 assigned commanding officers and training camps to the new corps.

Major General James F. Wade was named as commander of Third Army Corps, which was to assemble at Camp Thomas, Georgia.

[2] Brigadier General Royal T. Frank (USV) was assigned to command on September 4, and at the same time the corps was transferred to Anniston, Alabama, although a small detachment remained at Camp Thomas.