According to the pie chart titled "Population of Ethnic Groups in the United States (2014)", after whites, the largest ethnic group in the United States is Hispanic or Latino, which makes up 17.40 percent of the population.
The chart shows that about 30 percent of the US population is composed of the combined percentages of Black or African American (13.22 percent) and Hispanic or Latino (17.40 percent), totaling approximately 30.62 percent.
The smallest ethnic group listed is the Native Hawaiian and Other Pacific Islander, which accounts for 0.23 percent of the population.