<P> Several pieces of legislation signed into law in 1996 marked a turn towards harsher policies for both legal and illegal immigrants . The Antiterrorism and Effective Death Penalty Act (AEDPA) and Illegal Immigration Reform and Immigrant Responsibility Act (IIRIRA) vastly increased the categories of criminal activity for which immigrants, including green card holders, can be deported and imposed mandatory detention for certain types of deportation cases . As a result, well over 2 million individuals have been deported since 1996 . </P> <P> The terrorist attacks on September 11, 2001 affected American perspectives on many issues, including immigration . A total of 20 foreign terrorists were involved, 19 of whom took part in the attacks that caused the deaths of 2,977 victims, most of them civilians . The terrorists had entered the United States on tourist or student visas . Four of them, however, had violated the terms of their visas . The attack exposed long - standing weaknesses in the U.S. immigration system that included failures in the areas of visa processing, internal enforcement, and information sharing . </P> <P> The REAL ID Act of 2005 changed some visa limits, tightened restrictions on asylum applications and made it easier to exclude suspected terrorists, and removed restrictions on building border fences . </P> <P> In 2005, Senators John McCain and Ted Kennedy revived the discussion of comprehensive immigration reform with the proposal of the Secure America and Orderly Immigration Act, incorporating legalization, guest worker programs, and enhanced border security . The bill was never voted on in the Senate, but portions are incorporated in later Senate proposals . </P>

History of immigration policies in the united states