We sorted through Census data on general, Hispanic or Latino, Asian, and American Indian populations to identify the dominant flavors in the great melting pot.
It turns out the biggest group is not the English, who once controlled the 13 colonies, nor the Irish, who came over in vast waves in the 19th century, nor the Mexicans, who cross the southern border in large numbers in search of jobs.
The largest ethnic group, at 49,206,934
Of course, ethnicity is a tricky word, and if we were to count all Americans of Hispanic or Latino origin as one group, then that group would take a narrow lead with 49,215,563 people. For the purposes of this list, however, we are sticking with the most specific ethnicities tracked (in self-reporting surveys) by the Census.