The American primary tank in the Second World War was inferior to its German counterpart for all but the final months of the war. The U.S. tank evolved and demonstrated its superiority to the world in Operation DESERT STORM in 1991. This monograph examines the evolution of America's primary tank in the years between 1945 and 1991 focusing on three periods: the Second World War, the Korean War, and the 1973 Arab Israeli War. Each period examines the adversary, America's industrial capabilities, and the combat environment. Describing the adversary highlights there is a tangible threat to U.S. armored forces. In the face of this threat, the United States remained capable of building new more complicated and more expensive tanks, which demonstrates the industrial endowment required to meet the demands of the threat. An examination of the combat environment reveals why the U.S. Army and its armor force seemed so fixated on Europe as the next war's first battlefield. Ultimately, this paper serves to demonstrate that a tank series, such as the M1 Abrams family, is a required component in the U.S. Army's combined arms arsenal. As such, it is important that the aging Abrams, having served the Army in Operation Desert Storm and the Global War on Terror, continue to evolve in preparation for the next war.