An immigrant is a person who leaves the country that they were born in in order to live in another country permanently. From an American perspective, an immigrant is someone who was born in another country, takes up residency in the United States, and—if seeking to become a “naturalized” citizen—applies for U.S. citizenship under prevailing eligibility rules and immigration quotas set by Congress. Some immigrants leave their native lands in order to escape war, famine, and other hardships; these are called “push” factors. Others leave in search of education or economic opportunity; these are called “pull” factors. Waves of immigration, fueled by national and international events, have profoundly shaped the demographic makeup of the United States and its military forces. Likewise, wars with countries that send immigrants to the United States have disrupted longstanding immigration and naturalization policies. “The day after the Japanese attack on Pearl Harbor,” historian Steven Mintz writes, “Roosevelt suspended naturalization proceedings for Italian, German, and Japanese immigrants, required them to register, restricted their mobility, and prohibited them from owning items that might be used for sabotage, such as cameras and shortwave radios.” According to the Pew Research Center, the United States “has more immigrants than any other country in the world. Today, more than 40 million people living in the U.S. were born in another country, accounting for about one-fifth of the world’s migrants in 2016. The population of immigrants is also very diverse, with just about every country in the world represented among U.S. immigrants.”

For More Information:

“Immigration Terms and Definitions Involving Aliens,” Internal Revenue Service, accessed April 8, 2018,

Russell Contreras, “AP Explains: Immigrants in US Military Through History,” AP News, July 15, 2018,

Steven Mintz, “Immigration Policy in World War II,” Gilder Lehrman Institute of American History, accessed Nov. 7, 2018,

“Key Findings About U.S. Immigrants,” Pew Research Center, Sept. 14, 2018,

Philippe Legrain, Immigrants: Your Country Needs Them (New Jersey: Princeton University Press, 2007).