In 1986 the Immigration Reform and Control Act (IRCA) was passed by Congress to preserve the tradition of legal immigration while closing the door to illegal entry. IRCA placed requirements on U.S. employers to check the employment eligibility and identity of employees. Thus, the I-9 Form was developed.
In 1996 an additional piece of legislation was enacted that reduced the list of acceptable documents. This act is the Illegal Immigration Reform and Immigrant Responsibility Act. In February 2009, USCIS released an updated I-9 form.