General

• Angel Island Immigration Station Foundation
• Angel Island State Park
• Angel Island Immigrant Journeys of Chinese-Americans
• Detainees
• Ellis Island Home Page
• The History Channel: Ellis Island 
• Lower East Side Tenement Museum

African Americans

• African Immigration

Arab/Middle Eastern Americans

• The History of Arab Immigration to the US
  
• Patterns of Muslim Immigration 

Asian Americans

• Chinese Exclusion Act: Text of Act
• Chinese Immigration
• Japanese Immigration

European Americans

• German Immigration
• Germans in America
• Irish Immigration
• Italian Immigration
• Polish Immigration
• Russian Immigration
• Scandinavian Immigration

Jewish Americans

• The American Jewish Historical Society
• Center for Jewish History
• A Portion of the People: Three Hundred Years of Southern Jewish Life
• Jews in America

Hispanic Americans

• Mexican Immigration 

Primary Sources

• Internet History Sourcebook: Immigration
• The Foreign Immigrant in New York City 

Illegal Immigration

• Illegal Immigration and U.S. Border Security
• Center for Immigration Studies