Americans are the citizens and nationals of the United States. U.S. federal law does not equate nationality with race or ethnicity, but rather with citizenship. The U.S. has 37 ancestry groups with more than one million individuals. White Americans form the largest racial and ethnic group at 61.6% of the U.S. population, with non-Hispanic Whites making up 57.8% of the population. Hispanic and Latino Americans form the second-largest group and are 18.7% of the American population. Black Americans constitute the country's third-largest ancestry group and are 12.4% of the total U.S. population. Asian Americans are the country's fourth-largest group, composing 6% of the American population. The country's 3.7 million Native Americans account for about 1.1%, and some 574 native tribes are recognized by the federal government. People of American descent can be found internationally. As many as seven million Americans are estimated to be living abroad, and make up the American diaspora.