war was over. Reports were generally positive. Crews liked the improved offroad performance and reliability, but were most appreciative of the 75 mm main gun, which was a vast improvement over the 37 mm. The M24 was not up to the challenge of fighting tanks, but the bigger gun gave it a chance to defend itself when required. Regardless, its light armor still left it vulnerable. The M24's service during World War II was insignificant, as too few arrived too late to replace the M5s of the armored divisions, but the M24 saw extensive use in the Korean War. In the Korean War, M24s were the initial US tanks directed to combat the North Korean T-34-85s. The occupation troops in Japan from which the tanks were drawn were inexperienced and under-equipped due to rapid demobilization after World War II. The M24 fared poorly against these better armed, better armored, and better crewed medium tanks, losing most of their number while inflicting only minor damage on the T-34 units. Medium and heavy tanks M3 Lee The Medium Tank M3 replaced the M2 Medium tank and design commenced in July 1940, and the first "Lees" were operational in late 1941. Many were sent to the British where the tank was called the "General Lee" (after Confederate General Robert E. Lee), or "General Grant" (after General Ulysses S. Grant) depending whether they had U.S. specification or British specification turrets respectively. The U.S. Army needed a good tank and coupled with Great Britain's demand for 3,650 medium tanks immediately, the Lee began production by late 1940. The M3 was well armed and armored for the period, but due to design flaws (high silhouette, archaic sponson mounting of the main gun, below average offroad performance) it was not satisfactory and was withdrawn from front line duty as soon as the M4 Sherman became available in large numbers — the British managed to use the M3 successfully against the Imperial Japanese Army in Burma until 1945. When the U.S. entered the war, the M2 series medium tank design was obsolete with a 37 mm gun, 32 mm frontal armor, machine gun main armament and a very high silhouette. The success of the Wehrmacht in the French campaign, led by the Panzer III and Panzer IV, convinced the U.S. Army to immediately order a new medium tank armed with a 75 mm gun in a turret, which