The M4 Sherman, officially Medium Tank, M4, was the most numerous battle tank used by the United States and some other Western Allies in World War II. It proved to be reliable and mobile. In spite of being outclassed by German medium and heavy tanks late in the war, the M4 Sherman was cheaper to produce and available in greater numbers. Thousands were distributed through the Lend-Lease program to the British Commonwealth and Soviet Union. The tank was named after the American Civil War General William Tecumseh Sherman by the British.