The IRA was the most significant initiative of John Collier, who was President Franklin D. Roosevelt's Commissioner of the Bureau of Indian Affairs (BIA) from 1933 to 1945. He had long studied Indian issues and worked for change since the 1920s, particularly with the American Indian Defense Association. He intended to reverse the assimilationist policies that had resulted in considerable damage to American Indian cultures, and to provide a means for American Indians to re-establish sovereignty and self-government, to reduce the losses of reservation lands, and to build economic self-sufficiency. He believed that Indian traditional culture was superior to that of modern America, and thought it worthy of emulation. His proposals were considered highly controversial, as numerous powerful interests had profited from the sale and management of Native lands. Congress revised Collier's proposals and preserved oversight of tribes and reservations by the Bureau of Indian Affairs within the Department of Interior.