The 88th Infantry Division was an infantry division of the United States Army that saw service in both World War I and World War II. It was one of the first of the Organized Reserve divisions to be called into federal service, created nearly "from scratch" after the implementation of the draft in 1940. Previous divisions were composed of a core of either Regular Army or National Guard personnel plus draftees. Much of the experience in reactivating it was used in the subsequent expansion of the U.S. Army.

The United States Army Reserve (USAR) is a reserve force of the United States Army. Together, the Army Reserve and the Army National Guard constitute the Army element of the reserve components of the United States Armed Forces.