Census Bureau Population Estimates: PopClockshttp://www.census.gov/popclockDaily US and World Population Estimates from the US Census Bureauen-usNonehttp://blogs.law.harvard.edu/tech/rssUS Population Estimate: 320597205 on 2015-03-29 15:52:58http://www.census.gov/popclockFederal Government StatisticsWorld Population Estimate: 7233544231 on 2015-03-29 15:52:58http://www.census.gov/popclockFederal Government Statistics