Native Americans are the most exogamous ethnic group in the US. Being only 2% of the population has a lot to do with that, as well as strict tribal taboos against marrying any relative, not matter how distant. Many tribes also have rules against marrying within your clan or moiety.

A great deal of intermarriage between Native and European-Americans has happened in the last century. During the 20th century, many Native Americans left their tribal homelands for jobs, as part of military service, or as part of the 1950s US Federal Relocation program, which moved Indian families to urban centers. By the 1980s, 47.7–48.7% of American Indians married European-Americans.