WASHINGTON (RNN) - The U.S. population grew at the second slowest rate since the Great Depression, with just a 9.7 percent increase over the past 10 years.
U.S. Census Bureau Director Robert Groves said Tuesday the U.S. population is now more than 300 million, with 308,745,538 people calling the U.S. home in April 2010. In April 2000, the population was about 281.5 million.
During the Depression, the population increased 7.3 percent.
The census numbers are used to apportion the states' representation in the House of Representatives. Each state receives at least one seat, with the remaining 385 seats divided according to each state's population.
The census counted every resident living in the U.S. - whether they were documented or not - a method that has continued since the first census in 1790. The census did not include a question about citizenship.
The South and the West reported the largest gains in population, at 14.3 percent and 13.8 percent respectively. The region with the smallest growth is New England with 3.2 percent.
The state with the largest growth in population was Nevada at 35.1 percent. That's a decrease over a decade ago, when it experienced a growth of 66 percent. The state with the lowest growth in population was Michigan at 0.6 percent.
The state with the largest growth in the Northeast was New Hampshire, with a growth of more than 6 percent. In the South, Texas led the way with 20.6 percent growth over Louisiana, which had only 1.4 percent growth.
In the West, Nevada's 35.1 percent growth contrasted with that region's slowest state by population growth, Montana, with 9.6 percent.
The new numbers mean that beginning next year, 12 House seats will shift among states - a change that will affect 18 states.
Arizona, Florida, Georgia, North Carolina, Texas, Utah and Washington will all gain seats. Texas, with a gain of four seats, will take one-third of the new positions in Congress.
New York and Ohio - two states that helped Barack Obama secure the presidency in 2008 - will lose seats.
Population gains in red states will greatly benefit the Republican party, as only one of the states receiving new seats has a Democratic governor.
With the adjustment in population, each representative will now represent 710,767 U.S. citizens, up from 646,952 in 2000. The original members of the House represented just 34,000 people per person.
"We have grown," Groves said.
The most populous states are, in order: California, Texas, New York, Florida, and Illinois. New York is the only state that has ranked among the five largest in each decade since 1970.
New Jersey, one of the original 13 states in the 1790 census, has the largest population density, and Alaska has the lowest.
In 2009, the 2010 census was ranked as one of the federal programs most likely to fail.
But the Commerce Department was happy to announce that it completed the 2010 census on time and under budget.
The department was given $7.4 billion for its 2010 census budget, and it returned $1.87 billion to the U.S. Treasury, shaving a quarter off its budget, said Commerce Secretary Gary Locke.
Locke gave credit for the surplus to the American people, 74 percent of whom returned their census forms by mail, which allowed the Commerce Department to hire less door-to-door employees.
Still, 1.2 million people across the nation were hired to help with the census, including thousands of part-time workers, something that was good news for Americans in the wake of a struggling economy.
The first U.S. census was taken in 1790 and managed by Thomas Jefferson. U.S. marshals took 18 months to count people in the original 13 states.
The original census asked 10 questions, four less than the 2010 census. The 2010 census is the 23rd census to be taken in American history.
Copyright 2010 Raycom News Network. All rights reserved.