Humanities › Issues What Is the Definition of Illegal Immigration? Share Flipboard Email Print John Moore/Getty Images Issues Immigration Immigration Politics Inmigración en Español The U. S. Government U.S. Foreign Policy U.S. Liberal Politics U.S. Conservative Politics Women's Issues Civil Liberties The Middle East Terrorism Race Relations Crime & Punishment Animal Rights Canadian Government View More By Tom Head Civil Liberties Expert Ph.D., Religion and Society, Edith Cowan University M.A., Humanities, California State University - Dominguez Hills B.A., Liberal Arts, Excelsior College Tom Head, Ph.D., is a historian specializing in the history of ethics, religion, and ideas. He has authored or co-authored 29 nonfiction books, including "Civil Liberties: A Beginner's Guide." our editorial process Tom Head Updated January 30, 2019 Illegal immigration is the act of living in a country without government permission. In most U.S. contexts, illegal immigration refers to the presence of 12 million undocumented Mexican-American immigrants in the United States. Lack of documentation is what makes illegal immigration illegal; Mexican workers, recruited by U.S. corporations since the 1830s, have historically been allowed by the government to cross the border to work indefinitely -- initially on railroads and later on farms -- without interference. Immigration Enforcement Lawmakers have recently made more of an effort to enforce immigration paperwork requirements, partly as a result of terrorism-related fears stemming from the September 11th attacks, partly because of the emergence of Spanish as a second national language, and partly because of concerns among some voters that the United States is becoming less demographically white. Efforts to crack down on immigration paperwork violations have made life more difficult for U.S. Latinos, three-quarters of whom are U.S. citizens or legal residents. In a 2007 study, the Pew Hispanic Center conducted a poll among Latinos in which 64 percent of respondents stated that the immigration enforcement debate had made their lives, or the lives of those close to them, more difficult. Anti-immigration rhetoric has also had an effect on the white supremacist movement. The Ku Klux Klan has reorganized around the issue of immigration and is subsequently experiencing tremendous growth. According to FBI statistics, hate crimes against Latinos also increased by 35 percent between 2001 and 2006. At the same time, however, the current state of the law with respect to undocumented immigrants is unacceptable -- both because of the security risk posed by a completely porous border and because of the marginalization and labor abuses that undocumented immigrants often encounter. Efforts have been made to extend citizenship to undocumented immigrants under certain conditions, but these efforts have so far been blocked by policymakers who favor large-scale deportation.