The first deportation law in the United States was the Alien Act of 1798. Under this law, the president could deport any alien who was deemed dangerous. (A Naturalization Act was also passed that raised from five to 14 years the length of time an immigrant had to reside in the United States before being eligible for naturalization.) These measures were the result of growing hostility between the United States and France; with the accession to power of Napoleon Bonaparte, tensions eased dramatically, and no one was ever deported under the Alien Act.
Toward the end of the nineteenth century the Chinese Exclusion Act was passed to limit the number of Chinese immigrants into the United States, but it was not a deportation law. During the first decades of the twentieth century, however, a number of potentially subversive aliens were deported, particularly in light of the proliferation of anarchists and the spread of socialism. Events such as World War I and the 1918 Bolshevik revolution in Russia helped shape opinions in the United States, and immigration was viewed less and less favorably.
In the 1920s the issue was not so much deporting aliens as keeping them out; quota systems limited the number of immigrants to the United States. After World War II, the Cold War and a growing fear of Communist infiltration into the U.S. government resulted in more deportations for several years.
In the 1980s and 1990s an increasing number of illegal immigrants from South and Central America, Haiti, and Cuba tried to enter the United States. Most deportation cases today, in fact, are illegal immigration cases.