A look at how Congress has dealt with immigration in the past 25 years:
1986: The Immigration Reform and Control Act of 1986 both tightens controls on illegal immigration and extends amnesty for many illegal immigrants. It requires that employers attest to employees' immigration status and make it illegal to hire or recruit illegal immigrants. It also grants amnesty to some seasonal agricultural workers and to illegal immigrants who entered the United States prior to 1982 and have lived in the country continuously.
1990: The Immigration Act of 1990 created a lottery program that randomly assigned a number of visas, and increased the number of immigrants allowed into the country each year. The law also included exceptions for the English-language portion of the naturalization test.
1996: Under President Bill Clinton, several pieces of legislation are enacted that crack down on various facets of immigration. Specifically, there is a sharp increase in the categories of criminal activity for which immigrants, including permanent residents, can be deported. The laws also impose mandatory detention for certain types of deportation cases, and as a result deportation rates skyrocket.
Sept. 11, 2001: Terrorists attack New York and Washington, D.C., killing nearly 3,000 people. The events put immigration under a microscope because the attackers were foreigners, and change the way many politicians and Americans view immigration. Former Mexican President Vicente Fox goes so far as to say that if it were not for the attacks, Congress would have passed reform legislation that benefited Mexican emigration to America.
2003: The Supreme Court upholds mandatory detention regardless of flight risk for any immigrant offender, even permanent residents.
2005: In 2005 and 2006, Congress holds field hearings on immigration and border security across the country. The Senate introduces a significant bipartisan effort to create a path for legalization for many illegal immigrants.
December 2005: The House passes a bill criminalizing illegal immigrants, sparking massive pro-immigrant protests nationwide. The Senate refuses to take it up.
May 2006: Instead of the House bill, the Senate passes a tougher version of a bill crafted by Sens. John McCain, R-Arizona, and Ted Kennedy, D-Mass., which includes a path to legal residency for many illegal immigrants.