Introduction
The United States has often been characterized as a “nation of immigrants,” and with good reason. As a country that was literally founded by immigrants and their descendants, the United States, perhaps more so than any other country in the world, has been shaped by its immigrants.
Since 1850, immigrants have comprised a notable portion of the total U.S. population—between 5 and 15 percent.[1] Although the actual rate of immigration to the United States has varied drastically over time, immigration itself has remained a consistently significant factor in U.S. history, influencing the nation’s demographics, politics, culture, and economic growth.