the twenty-third united states census, known as census 2010 or 2010 census was a count of the population of the united states. it was done by the census bureau. it found that the population of the united states on april 1, 2010 was 308,745,538. this was an increase of 9.7 percent over the 281,421,906 people counted during the 2000 census. this was the twenty-third federal census.