Dzhokhar Tsarnaev became a citizen on September 11 of last year. He was one of 648 former residents of Kyrgyzstan to take the oath of naturalization, one of 757,434 new Americans to do so. With the country focused on how his family came to the country and proposals in the Senate and House revamping the immigration process, a little context on the history of immigration in the United States is in order.

Becoming a citizen is a multiple-step process. First, an immigrant becomes a permanent resident. Then, if his or her application is successful, a naturalized citizen. In another category are those who the country deports — which isn't always non-Americans. (Quartz offers a flowchart showing how it would work under legislation currently under discussion in Washington.)

Permanent residency

After a decline during World War II, the United States has been adding new permanent residents at a pretty consistently increasing rate. In 2012, just over a million people got their green cards. (The spike in 1991 was the result of the Immigration Act of 1990.)

In 2012, the plurality of those receiving permanent resident status were originally citizens of Mexico.

From 1922 to 1991, Kyrgyzstan was a part of the Soviet Union. Immediately prior to that, during the Russian Revolution, permanent resident approvals from Russia spiked, doing so again at the time that the country broke apart.

Naturalizations

Once a permanent resident has held that status for five years, he or she is eligible to apply for naturalization. Unsurprisingly, there's a bit of lead time — big increases in residents is followed by increases in naturalizations a few years later.

Last year, the most newly naturalized citizens were originally from Mexico, followed by the Philippines and India.

Not every applicant is granted status as a citizen of course. Denied applications are far more common now than they were even thirty years ago.

Between 1991 and 2011, the percent of applications that were denied increased dramatically.

Deportations

Deportation is a much trickier subject. There are a variety of reasons that people are deported — all of which are subject to political will. A New Yorker story published this week chronicles Mark Lyttle, a United States citizen who, following a variety of egregious mistakes, ended up being deported to Mexico. "The machinery," author William Finnegan writes, "exists, it has its political incentives, and, because its targets are weak, its accountability is slight, its impunity great." Finnegan notes that under President Obama, deportations increased dramatically, though they've largely plateaued.


2012 data is through August 25.

This is in part because Immigrations and Customs Enforcement has an unstated quota, according to Finnegan.

ICE officials deny that they have to meet deportation quotas, but the truth occasionally slips out. A 2010 memo from the head of ICE detention and removal operations exhorted the troops to remember "the Agency's goal of 400,000" deportations. … Between 1892 and 1997, the United States deported 2.1 million people. By the end of next year, if present trends continue, the Obama Administration will have deported that many in a mere six years.

Much of the increase under Obama has been an increase in the number of convicted criminals being deported. In January 2007, 39 percent of those deported were convicted criminals. In January 2012, that figure was 57 percent.

The picture provided by the data is open to interpretation. But, in general, it suggests that immigration in the United States hasn't changed a great deal over the past two decades. Forced emigration, however, has.

All data from the Department of Homeland Security's datasets on legal residency, naturalization, and removals.