Tanks of the United States saw limited action in the battle for Normandy as armored recovery vehicles with dummy guns. The M4 was the best known and most used American tank of World War II. Christened "Sherman" by the British, it was named for the famous US Civil War General, William Tecumseh Sherman. The M4 Sherman was a medium tank that proved itself in the Allied operations in North Africa, Europe and the Pacific theaters of war in World War II. The Sherman was a relatively inexpensive, easy to maintain and produce combat system. Similar to production efforts on the part of the Soviet Union
Opposition to the war in Afghanistan (2001–2014) entering an eleventh year on October 7, 2011 and marking for the U.S. the longest period of sustained warfare in its history – greater than the time the United States was involved in World War I, World War II and the Korean War combined.<ref name="War and Sacrifice in the Post-9/11 Era"></ref> The war in Afghanistan surpassed the length of official U.S. participation in the Vietnam War, 8 years and 5 months, in the spring of 2010 to become the longest-running U.S. war ever. According to a study by the RAND Corporation, an American think tank working for the U.S. military,