Statutory Authority:
The Immigration and Nationality Act (INA), signed in 1952 and amended many times since, contains the majority of federal statutes governing immigration law.
The Immigration and Nationality Act is codified in Title 8 of the U.S. Code ("Aliens and Nationality"), and in some other titles, such as Title 18 ("Crimes adn Criminal Procedure") and Title 22 ("Foreign Relations").
Case law:
Nexis Uni is a full-text news, business, and legal database with sources from around the world, including local, regional, national, and international newspapers, scholarly journals, trade journals, and popular magazines, television and radio broadcasts, and newswires and blogs. Legal sources include federal and state cases and statutes, including U.S. Supreme Court decisions since 1790. Also contains business information on U.S. and international companies (see Dossier section) and patent data (see TotalPatent One section).
Federal Regulations:
Laws enacted by Congress are interpreted and implemented by regulations issued by various agencies. These regulations are published in the Code of Federal Regulations (CFR). The CFR is arranged by subject title and generally parallels the structure of the United States Code.