The Immigration and Nationalist Act, known as the McCarran-Walter Act, eliminates all race-based quotas and replaces them with purely nationality-based quotas. To enforce the quotas, the law creates the Immigration and Naturalization Service. However, the Immigration Act of 1965, known as the Hart-Celler Act, abolishes national origins quotas, establishing separate ceilings for the Eastern and Western Hemispheres. Categories of preference are based on family ties, critical skills, artistic excellence, and refugee status.