score:14
One way to answer this question would be to look at United States Census Data to see how the government tracked race over time. In 1800, for example, the Census tracked free white males, free white females, all other free persons except Indians not taxed and slaves. (http://www2.census.gov/prod2/decennial/documents/1800-return-whole-number-of-persons.pdf)
The working paper, Historical Census Statistics on Population Totals By Race, 1790 to 1990, and By Hispanic Origin, 1970 to 1990, For The United States, Regions, Divisions, and States, from the U.S. Census Bureau identifies which racial and ethnic categories have been listed in the Census over time (although it does not specify how racial categories were phrases, e.g., black vs. African American). From the 1800 to 1850 Census (these are done every 10 years), only White and Black were counted. Beginning in 1860, American Indian, Eskimo, Aleut and Asian and Pacific Islander were counted. The first time Hispanic ethnicity appears to be considered is in the 1940 census, although it was not asked in all following censuses. (http://www.census.gov/population/www/documentation/twps0056/twps0056.html)