Demographics of the United States census population of ~31,000,000 http://en.wikipedia.org/wiki/Us_population Demographics of the United States - Wikipedia http://en.wikipedia.org/wiki/Us_population US population is about 313 million US population tripled population of ~31,000,000 http://en.wikipedia.org/wiki/Us_population http://en.wikipedia.org/wiki/Us_population http://en.wikipedia.org/wiki/Us_population