From Wikipedia, the free encyclopedia
Illegal immigration to the United States is the entry into the United States of foreign nationals in violation of United States immigration laws and also the remaining in the country of foreign nationals after their visa, or other authority to be in the country, has expired. These foreign nationals are referred to as 'illegal immigrants', 'undocumented immigrants' and 'unauthorized immigrants' in American discourse.

The United States had nearly open borders until 1924,[1][2][3] with only 1% of those trying to get in rejected, usually because they failed the required mental or health exam.[4][5] Earlier immigration controls were enacted with the Page Act of 1875 and Chinese Exclusion Act of 1882.[6] The Immigration Act of 1924 established visa requirements and enacted quotas for immigrants from specific countries.[4]

Estimates in 2015 put the number of unauthorized immigrants at 11 million, representing 3.4% of the total U.S. population.[7] The population of unauthorized immigrants peaked in 2007, when it was at 12.2 million and 4% of the total U.S. population.[7][8] Since the Great Recession, more undocumented immigrants have left the United States than have entered it, and illegal border crossings are at the lowest levels they have been in decades.[9][10][11][12] In 2014, unauthorized immigrant adults have lived in the U.S. for a median of 13.6 years, with approximately two-thirds having lived in the U.S. for at least a decade.[7] In 2012, 52% were from Mexico, 15% from Central America, 12% from Asia, 6% from South America, 5% from the Caribbean, and another 5% from Europe and Canada.[13]

Research shows that illegal immigrants increase the size of the U.S. economy, contribute to economic growth, enhance the welfare of natives, contribute more in tax revenue than they collect, reduce American firms' incentives to offshore jobs and import foreign-produced goods, and benefit consumers by reducing the prices of goods and services.[8][14][15][16][17] Economists estimate that legalization of the illegal immigrant population would increase the immigrants' earnings and consumption considerably, and increase U.S. gross domestic product.[8][18][19][20][21][22]

There is no evidence that illegal immigration increases the rate of crime in the United States.[23] There is scholarly consensus that illegal immigrants commit less crime than natives.[24][25] Sanctuary cities – which adopt policies designed to not prosecute people solely for being in the country illegally – have no statistically meaningful impact on crime or reduce the crime rate.[26][27] Research suggests that immigration enforcement has no impact on crime rates.[28][29][26]