III Corps' colorful history dates from 1918 when the Corps served in World War I, winning battle streamers for the Aisne-Marne, Lorraine, and the Meuse-Argone campaigns. 

Inactivated in 1919, the Corps was reactivated in 1940 to train combat divisions. During World War II the Corps was deployed to The European Theater of Operations and earned the name "Phantom Corps" by hitting the enemy when least expected. It won campaign streamers in Northern and Central Europe, and established the Remagen Bridgehead, enabling the Allies to secure a foothold in Germany. 

Inactivated in 1946, III Corps was reactivated in 1951 and served on active duty until 1959. Inactivated that year, it quickly returned to duty at Fort Hood during the Berlin Crisis in 1961. In 1962, III Corps was designated as part of the U.S. Army Strategic Army Corps. 

During the Vietnam conflict, III Corps trained and deployed two Field Force Headquarters and many combat and combat service support units totaling more than 100,000 personnel. 

In recent years, III Corps forces have fought in and supported operations worldwide, to include Grenada, Panama, Honduras, Saudi Arabia, Kuwait, and Iraq, and provided humanitarian support for Operation Restore Hope in Somalia. III Corps elements provided support for Operation Joint Endeavor in Bosnia and Herzegovina. 

For many years, the primary focus of the III Corps was the reinforcement of NATO. As the world and the U.S. Army have changed the Corps has also changed and broadened its focus to be ready to deploy anywhere, anytime and win.