On July 15, 1834, Brigadier General Henry Leavenworth died near Washita Falls in the Cross Timbers region of Indian Territory (present-day border of Oklahoma and Texas). Leavenworth served as Regimental Commander of the 3rd Infantry Regiment from 1825-1834. In 1834, Leavenworth received orders to take command of the Left Wing of the Western Department of the Army in February 1834, and was later promoted to brigadier general.

Under the Leavenworth’s leadership, the Regiment established what was to become Fort Leavenworth in 1827. During his tenure, the Regiment was active along the border of the United States and the Choctaw Nation. Jefferson Barracks, Missouri was used as a base of operations. It was there Leavenworth started an infantry school under orders from the Army.