Texas has once again topped the national growth chart, adding 529,000 people since the 2010 Census, though its rate of growth has slowed slightly.
The U.S. growth rate from April 2010 to July 2011 also slowed, falling to 0.92 percent, the lowest since the mid-1940s, according to census estimates released Wednesday.
"The nation's overall growth rate is now at its lowest point since before the baby boom," census Director Robert Groves said.
The country grew by 2.8 million people to 311.6 million.
The biggest gainers behind Texas were California (438,000), Florida (256,000), Georgia (128,000) and North Carolina (121,000).
The five states accounted for slightly more than half of the nation's population growth over the 15 months.
Washington, D.C., grew faster than any state, increasing by 2.7 percent over the period. Texas was the next fastest, at 2.1 percent, followed by Utah (1.93 percent), Alaska (1.76 percent) and Colorado (1.74 percent).
Steve Murdock, a Rice University professor and former census director, said the new numbers reflect a small decline in Texas' phenomenal growth over the last decade, when it grew by 20.3 percent, swelling the population by 4.3 million.
Adjusting the new Texas numbers to a yearly rate, the state's population grew about 1.7 percent, he said.
"That's still quite substantial compared to other states," Murdock said. "The in-migration is down, and I think it's clearly a continuation of a pattern.
"I think it will be surprising if we didn't see a little slower growth over the next couple of years."
Much of Texas' gain was homegrown, with 493,650 births far surpassing the 205,171 deaths, a natural increase of 288,479.
Net migration to Texas added 238,956 people, including 145,315 domestic movers and 93,641 international newcomers.
State demographer Lloyd Potter said the in-migration confirms that the Texas economy continues to fare relatively well nationally and internationally.
"A lot of the growth is still being driven by in-migration. That's coming from other states with California being the biggest contributor to Texas," he said.
California remains the most populous state, with 37.7 million residents. Texas is second at 25.7 million, followed by New York (19.5 million), Florida (19.1 million) and Illinois (12.9 million).
Only three states lost population: Michigan (-7,448), Rhode Island (-1,265) and Maine (-173).
Nevada, the fastest-growing state by percentage (35.1 percent) from 2000 to 2010, was ranked 27th in growth, increasing by just 0.8 percent during the 15 months.
"The places that have been struggling are continuing to struggle," Murdock said.
Regionally, the South and the West grew by 1.3 percent, followed by the Northeast (0.4 percent) and Midwest (0.3 percent).
The new numbers reflect the continued trend of slowed mobility across the nation.
Census data released last month showed that only 11.6 percent of Americans changed residences in 2010, the lowest rate since the Census Bureau began collecting such statistics in 1948.
Texas also led the 2010 mobility list, with the addition of nearly 75,000 people.
But that's less than half the 200,000 annual migrants to the state in 2000-10 as the faltering economy limited employment opportunities and made it difficult for job hunters to sell their homes if they found a new workplace.
Steve Campbell, 817-390-7981