Encyclopedia of American Immigration [print] Provides a very comprehensive set which provided detailed information on all major immigrant groups. The set also includes hundreds of photographs and primary source documents.
History Reference Online An online collection of hundreds of history reference titles published by ABC-Clio. Can be browsed by subject categories or full-text searched by keyword. For a very general search, try immigration united states.
Immigration in America Today [print] A one volume encyclopedia which focuses on the various aspects of immigration; does not include information on any particular ethic groups or nations of origin.