The United States enters 2011 with a population of more than 310.5 million people, according to a U.S. Census Bureau estimate. Note that that’s an estimate (taken from their neat U.S. “population clock”); according to their official, enumerated count, the U.S. population as of April 1, 2010 was 308,745,538 people. (The difference is presumably population growth over the last nine months of the year.)
The 310.5 million figure is a 2.1 million person increase (about a 0.6 percent increase, if my math is correct) from their U.S. population estimate (308.4 million) at the end of 2009.
Delving a bit deeper, there’s one birth every eight seconds and one death every 12 seconds; the population goes up by one international migrant (net) every 45 seconds. All told between births, deaths, and immigration we add one new person to the population every 15 seconds—about the time it took you to read this paragraph.
Looking at the entirety of the decade, the U.S. population grew 9.7 percent from its 2000 size of 281,421,906 to the 308.7 million of April 1. California is the most populous state, with 37.3 million people, and Wyoming the least so, with 563,626 people. Texas was the fastest gaining state in terms of numerical population, up 4.3 million people over the decade; Nevada was the state that gained the most as a percentage of its 2000 count, with a 35.1 percent increase. The South gained 14.3 million people over the decade, while the Northeast only added 1.7 million (the West added 8.7 million and the Midwest 2.5 million). Puerto Rico actually got smaller, losing 2.2 percent of its population.
Of course the decennial census brings a reshuffling of congressional seats. Texas will gain four House seats, Florida two, and the delegations from Arizona, Georgia, Nevada, South Carolina, Utah, and Washington will each grow by one member. On the flip side, New York and Ohio will each lose two seats while Illinois, Iowa, Louisiana, Massachusetts, Michigan, Missouri, New Jersey, and Pennsylvania will each decline by one seat.