Other migrant groups were limited in number by the National Origins quota system, which designated national quotas based on census ratios from 1890. These ratios heavily favored Western European nations and older migrant groups, such as the English, Irish, and Germans. The ratios attempted to limit the rising number of Southern and Eastern European immigrants. The National Origins quota system provided limited family reunification as a means for chain migration and placed a preference on naturalization. If an immigrant became a U.S. citizen, he or she had the ability to obtain non-quota visas for more family members, but as a resident that number was capped annually. Additionally, the Immigration Act of 1924 formally opened the door to chain migration from the entire western hemisphere, placing that group under non-quota status.