Ramon and Anita Ruiz (plaintiffs) were Papago Indians and United States citizens. IN 1940, they left the Papago reservation in Arizona to seek employment 15 miles away in a town called Ajo. Ramon Ruiz worked at the nearby Phelps-Dodge copper mine. In July 1967, the mine shut down because of a strike. During the strike, Ramon Ruiz applied for assistance benefits provided by the Snyder Act with the Bureau of Indian Affairs (BIA). The BIA denied benefits on the sole ground that the Ruizes resided outside the boundaries of the Papago reservation. A policy in the Indian Affairs Manual, which had been in effect since 1952, limited eligibility for benefits to Indians living on reservations. The Ruizes filed a class action against the Secretary of the BIA (defendant) claiming statutory entitlement to the benefits. The district court rendered summary judgment for the BIA. The court of appeals reversed, holding that the residency requirement was inconsistent with the Snyder Act. The Supreme Court granted certiorari.