Until the 1990s, the term most commonly used for those who entered the United States illegally was illegal alien. An alien was defined by the Immigration and Naturalization Service (INS) as “any person not a citizen of the United States.” Any alien who enters and resides in the country in violation of immigration law is an illegal alien. During the 1990s, the government and governmental authorities increasingly used the term unauthorized resident as a synonym. The term most commonly used in Canada is undocumented migrant. Aliens, whether legal or illegal, still enjoy most of the rights and protections afforded by both governments. Unlike citizens, however, they are subject to deportation for breaches of the law. As potential immigrants around the world began to perceive the potential for securing better jobs, education, and health care in the 1970s in the United States and Canada and increasingly found means for getting there, illegal immigration became a major policy concern. It also led to a new wave of anti-immigration activism, particularly in the American Southwest, and a public debate that had still not been resolved in the first decade of the 21st century. Until 1917, the United States had a largely open immigration policy; the biggest immigration questions revolved around legal, rather than illegal, immigration. Between 1875 and 1917, a number of restrictive measures were passed to exclude prostitutes, convicts, “lunatics,” “idiots,” and the indigent (see Immigration Act (1906); Page Act), but these affected few people. More significant were the Chinese Exclusion Act (1882) and the Gentlemen’s Agreement (1907), which led to the exclusion of most Chinese and Japanese laborers. Although some laborers found their way into the country, mainly through colonial Hawaii, where they were still allowed as laborers, illegal immigration did not affect the country generally. The tight restrictions of the Emergency Quota Act of 1921 and the Johnson-Reed Act of 1924, however, led to a flood of illegal immigration in the 1920s. Canada offered some cooperation, but Mexico was unresponsive, and Chinese immigrants especially continued to pour across both borders. As early as 1904, Bureau of Immigration inspectors routinely patrolled almost 2,000 miles of Mexican border, but the 75 agents assigned to the task were scarcely able to prevent illegal entry. With drastically reduced quotas following the immigration reform of 1924 came establishment of the U.S. Border Patrol, an enforcement agency of the Department of Labor. The dramatic increase in immigration after 1965 was in large measure a function of the provisions of the Immigration and Nationality Act of 1965 and government perception of cold war needs to exclude especially Cubans and Vietnamese from the ordinary provisions of immigration policy. At the same time, however, illegal immigration exploded, as legal migrant laborers under the Bracero Program became illegal immigrants once the program was ended (1965). With the INS understaffed and U.S. employers exempt from criminal prosecution for hiring illegal immigrants, cheap foreign labor continued to pour into the country. Between 1970 and 1997, more than 30 million illegal immigrants were apprehended, though deportations were often difficult, and millions more eluded interception and entered the labor force. The number of unauthorized immigrants in the United States rose dramatically in the 1990s. An INS report of February 1997 showed that there were an estimated 5 million illegal immigrants in the United States as of October 1996; four years later, the number had risen to 7 million (8.7 million according to the U.S. Census Bureau), further heightening the public debate over American responsibility toward poor, illegal immigrants. Almost 70 percent of unauthorized residents in 2000 were from Mexico, and another 14 percent from El Salvador, Guatemala, Colombia, Honduras, Ecuador, and the Dominican Republic. About 40 percent entered with tourist or worker visas but failed to return to their home countries when the visas expired. After years of debate, the U.S. Congress passed the Illegal Immigration Reform and Immigrant Responsibility Act in 1996, which increased the Border Patrol, provided for stiffer penalties in trafficking undocumented aliens, and made deportation easier. In March 2000, Vice President Al Gore proposed to expand the 1986 Immigration Act, which granted residency to immigrants who had lived continuously in the United States since 1972, to include those who had lived in the United States since 1986. As a result, some 500,000 undocumented immigrants were granted residency. Canadian economic opportunities were fewer than in the United States, the attitude toward non-British immigrants more hostile, and the distances greater, so the incidence of illegal immigration was less and had less national impact. With the rapid progress of decolonization around the world, however, and passage of the immigration regulations of 1967, two significant waves of undocumented immigration occurred. Between 1970 and 1973, more than 200,000 people applied for landed immigrant status. Under Section 34 of the regulations, it became permissible to apply within Canada and be guaranteed the right of appeal if denied. Thousands of potential immigrants from around the world took advantage of this administrative loophole, realizing that there would be a huge backlog of cases that would permit settlement. With up to 8,700 applications a month by October 1972, the Canadian government revoked Section 34 while offering the Adjustment of Status Program, essentially an amnesty. By the end of 1973, about 52,000 previously undocumented immigrants had been granted landed immigrant status. With economic depression looming in 1980, public opposition to immigration began to increase, along with the number of undocumented immigrants. Most of the increase involved claims for refugee status, many of which were bogus and clearly designed to give undocumented immigrants an opportunity to gain a foothold in Canada (see Honduran immigration). Provisions of Bill C-55 and BILL C-84, which went into effect in 1989, streamlined the refugee determination process, increased penalties for those transporting undocumented migrants, and enhanced the government’s powers of deportation. By the late 1990s, some were estimating that as many as 16,000 illegal immigrants were entering Canada annually, at a cost of up to $50,000 in social benefits for each immigrant. With many of the 19 hijackers involved in the terrorist bombings of September 11, 2001, being illegal aliens, the debate over illegal immigration was renewed in both the United States and Canada, and more stringent measures were introduced for screening and tracking immigrants and for deporting illegal aliens. In the first decade of the 21st century, illegal immigration from Mexico was the top U.S. concern and led to high-level discussions between the two governments. Canada’s biggest concern was human trafficking from China and the high number of refugee claims by Chinese immigrants. See also nativism.