The unfortunate truth is that we really don't know for sure, but we can make educated guesses. Naturalization expert Eric Cohen of the Immigration Legal Resource Center says that naturalization numbers tend to shoot up during times of increased anti-immigrant rhetoric and action by the government. They also rise during presidential election years. 1944, 1996, 2000 and 2008 were all presidential election years.

 

The peak in 1944 likely had to do with U.S. involvement in World War II, Cohen said. The U.S. entered the war on Dec. 7, 1941, after Japan's attack on Pearl Harbor. In addition, Japanese American internment was at its height in 1944. On Dec. 18, 1944, the U.S. Supreme Court ruled in Korematsu v. United States that the federal government's roundup and imprisonment of American citizens and residents of Japanese descent were constitutional. 

 

In 1986, President Ronald Reagan signed the Immigration Reform and Control Act (IRCA). The act was a major milestone in immigration law in the U.S. It increased border enforcement, imposed penalties for employers who hired undocumented people and provided legalization and a path to citizenship for millions of immigrants who had lived undocumented in the U.S. for at least five years. By 1996, many of those individuals had become eligible to apply for naturalization.

 

The years of the mid-90s were hotbeds of anti-immigrant legislation such as the Clinton administration's welfare reform which barred many immigrants and refugees from receiving state-funded resources like Medicaid and food stamps, Cohen said. 

 

The peaks in 2000 and 2008 both may have been caused by a combination of presidential campaign rhetoric and increases in naturalization fees. Meaning that permanent residents who had been thinking about becoming citizens rushed to do so before the application fee went up. It is relevant to note that the naturalization application fee has risen over 700% since the late 1990s.

 

Also, keep in mind that the naturalization process takes time, so the individuals behind these data peaks likely began the process in a previous year.