its value as a weapon had been clearly demonstrated. In addition to the light and heavy categories of American-produced tanks of World War I, a third classification, the medium, began receiving attention in 1919. The meaning of the terms light, medium, and heavy tanks changed between the wars. During World War I and immediately thereafter, the light tank was considered to be up to 10 tons, the medium (produced by the British) was roughly between 10 and 25 tons, and the heavy was over 25 tons. Later, during World War II, increased weights resulted in light tank designs often weighing over 20 tons, medium tank designs weighing over 30 tons, and heavy tank designs weighing over 60 tons. Patton and Eisenhower remained involved in developing the armored arm, which found a temporary home at Camp Meade under Rockenbach's command. In particular, the two men formulated theory and doctrine for the use of tanks in mass formations to achieve breakthroughs and carry out flanking attacks. They were met with vigorous opposition to their ideas from senior army officers, who favored the use of armor to support the infantry, not as a separate arm conducting independent operations. Congress took this view as well, when enacting the 1920 legislation that dissolved the Tank Corps as a separate entity. The National Defense Act of 1920 placed the Tank Corps under the Infantry. Patton had argued for an independent Tank Corps, and understood that tanks operating with Cavalry would stress mobility, while tanks tied to the Infantry would emphasize firepower. However, the supply of slow World War I tanks and the subordination of tanks to the infantry branch impeded the development of any role other than direct infantry support, so the United States moved slowly in the development of armored and mechanized forces, which resulted in a significant cut in funding for tank research and development. Patton, convinced there was no future in tanks, applied and received a transfer to the cavalry in September 1920. Eisenhower got out two years later, in January 1922, when he was assigned to the staff of an infantry brigade in Panama. The U.S. War Department considered that two types of tanks, the light and the medium, should fulfill all missions. The light tank was to be transportable by truck, and not exceed 5 tons gross weight. The medium tank was not to exceed 15 tons, so as to bring