The 159th Infantry Regiment was an infantry regiment of the United States Army. It served as a part of the 40th Infantry Division for most of its history before deploying in World War II as a part of the 7th Infantry Division.
The regiment traced its lineage to the 2nd Infantry Battalion of the California National Guard, organized on 12 December 1879 from existing companies.
World War I
The 159th Infantry Regiment was first constituted and activated in the Regular Army in the 80th Infantry Brigade, 40th Infantry Division. It served with the division until 1942.
World War II
On 1 July 1940, the 7th Infantry Division was reactivated at Camp Ord, California, under the command of Major General Joseph W. Stilwell.
The 7th Infantry Division was assigned to III Corps of the Fourth United States Army, and that year it was sent to Oregon for tactical maneuvers. Division units also practiced boat loading at the Monterey Wharf and amp