An official website of the United States government

Here's how you know

Official websites use .mil

A .mil website belongs to an official U.S. Department of Defense organization in the United States.

Secure .mil websites use HTTPS

A lock () or https:// means you’ve safely connected to the .mil website. Share sensitive information only on official, secure websites.

Browse History by Month

This Month in First Army History

4 July

1918

On the 4th of July 1918, the American I Corps assumed command of a portion of the Chateau-Thierry sector, which included the US 1st Infantry Division. These troops would be the first Americans to see combat in WWI.

On the 4th of July 1918, Lieutenant Colonel Hugh A. Drum was selected to be the Chief of Staff for First US Army. This would see the first formal organization of the future First U.S. Army.

24 July

1918

On 24 July 1918, General Headguarters, American Expeditionary Force, issued General Order Number 120 which announced the organization of the First US Army, effective 10 August 1918.