As with many developments in American Indian history, urban migration is a complex topic and fraught with overtones - and overt expressions - of racism and paternalism. From 1952 to 1973, the Bureau of Indian Affairs sponsored the Voluntary Relocation Program, which encouraged Indians to move from tribal lands to cities. In return, participants received short-term assistance with housing and job training. About 100,000 people participated in the program. Many, many more migrated to cities in the years following World War II, in response to economic pressures, individual desires and changes in other Indian-affairs policies in the federal government.