The 101st Airborne Division is an infantry division in the United States Army. It was called an "airborne" division because, as a paratrooper unit, it used airplanes to go into battle. It is most famous its defense of Bastogne at the Battle of the Bulge. The division later fought in the Vietnam War, including the Battle of Hamburger Hill. It also fought in the Gulf War, War in Afghanistan, and War in Iraq.