census.gov
Let's go through the numbers (estimates for July 2015):
>Population estimates, July 1, 2015 - 321,418,820
>Population estimates base, April 1, 2010 - 308,758,105
Change since 2010: +12,660,715
>White alone, not Hispanic or Latino, percent, July 1, 2015 - 61.6%
>White alone, not Hispanic or Latino, percent, April 1, 2010 - 63.7%
Change: -2.1%
>Hispanic or Latino, percent, July 1, 2015 - 17.6%
>Hispanic or Latino, percent, April 1, 2010 - 16.3%
Change: +1.3%
>Black or African American alone, percent, July 1, 2015 - 13.3%
>Black or African American alone, percent, April 1, 2010 - 12.6%
Change: +0.7%
>Asian alone, percent, July 1, 2015 - 5.6%
>Asian alone, percent, April 1, 2010 - 4.8%
Change: +0.8%
>Two or More Races, percent, July 1, 2015 - 2.6%
>Two or More Races, percent, April 1, 2010 - 2.9%
Change: -0.3%
>American Indian and Alaska Native alone, percent, July 1, 2015, (V2015) - 1.2%
>American Indian and Alaska Native alone, percent, April 1, 2010 - 0.9%
Change: +0.3%
>Native Hawaiian and Other Pacific Islander alone, percent, July 1, 2015 - 0.2%
>Native Hawaiian and Other Pacific Islander alone, percent, April 1, 2010 - 0.2%
Unchanged