The Immigration and Nationality Act, or INA, was created in 1952.  Before the INA, a variety of statutes governed immigration law but were not organized in one location.  The McCarran-Walter bill of 1952, Public Law No. 82-414, collected and codified many existing provisions and reorganized the structure of immigration law.  The Act has been amended many times over the years, but is still the basic body of immigration law.

The INA is divided into titles, chapters, and sections.  Although it stands alone as a body of law, the Act is also contained in the United States Code (U.S.C.).  The code is a collection of all the laws of the United States.  It is arranged in fifty subject titles by general alphabetic order.  Title 8 of the U.S. Code is but one of the fifty titles and deals with "Aliens and Nationality".  When browsing the INA or other statutes you will often see reference to the U.S. Code citation.  For example, Section 208 of the INA deals with asylum, and is also contained in 8 U.S.C. 1158.  Although it is correct to refer to a specific section by either its INA citation or its U.S. code, the INA citation is more commonly used.