The term race is defined as a racial group that is socially set apart because of obvious physical differences. Such as hair color, earlobe shapes, the color of one’s skin, the hair texture, and so on for the obvious. On the United States the skin color is another obvious difference the main obvious difference. People in the Unites States have learned informally that skin color is important and hair color is unimportant. Americans have traditionally classified and classify themselves as either Black or White.
There is no in-between state except for people readily identified as Native Americans and Asian Americans. The designation of a racial group emphasizes physical differences as opposed to cultural distinctions.