First Army Division East was established by Department of the Army Permanent Order 156-7 to provide training and readiness oversight and mobilization operations for an area of responsibility spanning 27 states and territories east of the Mississippi River.

First Army Division East is responsible for mobilizing, training, readiness oversight and deploying the United States' Reserve and National Guard Soldiers, and selected Sailors and Airmen along with members of multiple interagency and governmental entities.

The division is organized into five brigades located throughout the eastern United States with 52 total battalions.

Division East currently operates three mobilization training centers located at Camp Atterbury Joint Maneuver Training Center, Indiana; Camp Shelby Joint Forces Training Center, Mississippi; and Joint Base McGuire–Dix–Lakehurst, New Jersey.

This article incorporates public domain material from websites or documents of the United States Army.