The U.S. Census Bureau announced today that the country's population was 308,745,538 on April 1, 2010. That represents an increase of 9.7 percent over the 2000 U.S. resident population of 281,421,906.
The numbers will have an impact on Congress next year. The steady migration to the South and West will be a boon for Republicans, with GOP-leaning states led by Texas picking up House seats.
The most populous state was California (37,253,956); the least populous, Wyoming (563,626). The state that gained the most numerically since the 2000 Census was Texas (up 4,293,741 to 25,145,561) and the state that gained the most as a percentage of its 2000 Census count was Nevada (up 35.1% to 2,700,551).
"The effect of the official 2010 population counts at the state level on congressional apportionment is a shift of 12 seats," said Census Bureau Director Robert Groves. "Those states gaining seats include Arizona, Florida, Nevada, Texas, Utah and Washington."
The U.S. is still growing quickly relative to other developed nations. The population in France and England each increased roughly 5 percent over the past decade, while in Japan the number is largely unchanged and in Germany the population is declining. China grew at about 6 percent; Canada's growth rate is roughly 10 percent.
"We have a youthful population that will create population momentum through a large number of births, relative to deaths, for years to come," said Mark Mather, an associate vice president at the Population Reference Bureau, a private firm in Washington that analyzes census data. "But demographers generally expect slower growth in the first decade of the 21st century."
Politically, Texas stands to gain up to four seats due to a burgeoning Hispanic population and a diversified economy that held up relatively well during the recession, according to projections by outside analysts using census estimates. Other winners are GOP-leaning Arizona and Florida, which could add one or two seats.
The projections do not account for overseas U.S. military personnel and their families, who are typically counted at military bases in the U.S. The Census Bureau obtains Pentagon records on overseas military and adds them to the resident count before allocating the House seats. In 2000, North Carolina beat out Utah for the last House seat because of its strong Army presence.
The release of state apportionment numbers is the first set of numbers from the 2010 census. Beginning in February, the Census Bureau will release population and race breakdowns down to the neighborhood level for states to redraw congressional boundaries.
Louisiana, Virginia, New Jersey and Mississippi will be among the first states to receive their redistricting data next February.
The 2010 census results also are used to distribute more than $400 billion in annual federal aid and will change each state's Electoral College votes beginning in the 2012 presidential election.
The Associated Press contributed to this report.
