The United States' immigrant population has surpassed 42 million, making the U.S. the most desired destination country for migrants. The nation has absorbed millions from India, Russia, China, Bangladesh and, most notably, Mexico — the country of origin for 29 percent of the U.S. immigrant population. In recent years, the 2,000-mile border between Mexico and its northern neighbor has been crossed by 11.7 million U.S.-bound Mexican migrants, the largest wave of immigration from a single country to the United States in history. With the surplus of Mexican migrants came the criminalization of immigrants.

Influxes of immigrant populations aren't new in American history. In fact, just a little over a century ago, the U.S. experienced a urge of immigrants from Germany. From 1890 to 1919, 18.2 million immigrants, hailing mainly from Europe (88 percent), entered the U.S. Germans were the majority of those immigrating to the U.S. (30 percent), followed by the United Kingdom (18 percent), Canada (7 percent) and later Italy (21 percent).

German immigrants topped the list of entering immigrants in the early 1900s, making up the biggest immigrant group in 17 states and the District of Colombia. Second to Germans were individuals arriving from Russia and the USSR (11 percent or 1.6 million). Mexican immigrants were the largest immigrant group in only three states (Arizona, New Mexico and Texas). Congress passed legislation in 1965, opening the nation's borders to foreign settlers looking for opportunity. The move attracted mainly those from Latin America (50 percent) and Asia (30 percent), though the goal was presumably to attract more European settlers. Today, 1 in 5 people living in California, New York, New Jersey or Florida are foreign-born.

In 1860, China was the source of most of the foreign-born immigrants (39.7 percent) in California. Presently, China holds the title for the second-highest number of immigrants.

With five times the Chinese immigrant population, the majority of immigrants today come from Mexico (29 percent or 11.7 million). Mexican immigrants dominate the foreign-born populations in New Mexico (72.4 percent), Arizona (60.2 percent), Texas (59.7 percent), and Idaho (53.5 percent). Canadians have the largest numbers in Maine, New Hampshire, Vermont, North Dakota and Montana.

But, with immigrants arriving from multiple nations over the last few centuries, how did immigration become a Latino issue? And, how did immigration become illegal? Aviva Chomsky, author of "Undocumented: How Immigration Became Illegal" and "They Take Our Jobs! and 20 Other Myths about Immigration" recently appeared on "Democracy Now," where she discussed how systematic prejudice against Mexicans and other migrant workers has influenced present day immigration policies and law.

Legislators have thrown boulders and barriers in the path of Mexicans seeking citizenship — while citizenship has long been much more easily granted to European immigrants. Chomsky discussed the criminalization of migrants in the land of the free and the fact that many, including the Chinese, are "legally defined as racially ineligible to citizenship."

"People have in mind Ellis Island; they have in mind the European immigrants; they have in mind the people who, under U.S. law, have been considered immigrants since really the founding of the country. We need to think about how immigration and citizenship work together. That is, those who the law has considered immigrants are those who were considered to be potential citizens," said Chomsky, a professor of history and coordinator of Latin American studies at Salem State University in Massachusetts.

"Mexican border crossing was never restricted because Mexican labor was so utterly necessary in the southwest of the United States, and because Mexicans were not considered immigrants, their immigration did not have to be restricted. They were considered to be workers, legally discriminated against for what were considered racial grounds, which is they were so-called 'Mexican.' That was perfectly legal ... to deprive them of citizenship was perfectly legal."

Chomsky added that the illegality of Mexican migration began in 1965, when a quota was placed on Mexican migration, and the tens of thousands of Mexicans, who had just been beckoned to cross the border legally, often recruited, and at times coerced, were suddenly unwanted. Movement did not stop. But overnight it became illegal, and it led to the justified mistreatment of Mexican workers because they were "criminals."

The amount of money allocated for border security exemplifies the nature of immigration policies and its anti-Mexican agenda. U.S. policies are responsible for uprooting and displacing families because of where they're from. Undocumented immigrants, who've been forced back across the border, are experiencing this at a rate that's never been so widely applied to another ethnic group in U.S. history.