Big cities surpassed the rate of growth of their surrounding suburbs at an even faster clip, a sign of America's continuing preference for urban living after the economic downturn quelled enthusiasm for less-crowded expanses.
Farther-out suburbs known as exurbs saw their growth slip to 0.35 percent, the lowest in more than a decade.
Economists generally had played down the recent city boom as an aberration, predicting that young adults in the recovering economy would soon be back on the move after years of staying put in big cities. But the widening gains for cities in 2012 indicate that young people - as well as would-be retirees seeking quieter locales - are playing it safe for a while longer in dense urban cores, where jobs may be easier to find and keep.
Prior to 2011, suburbs had consistently outpaced big cities since 1920, with the rise of the automobile.
The new census estimates are a snapshot of population growth as of July 2012. The Associated Press sought additional analysis from William H. Frey, a demographer at the Brookings Institution, and Kenneth Johnson, a senior demographer at the University of New Hampshire.
Cities with booming regional economies continue to see the biggest gains - from Seattle and San Francisco to Austin, Texas, Raleigh, N.C., and Washington, D.C., locales seeing a burst of new apartment construction.
"Cities have become more appealing to young people, with more things to do and places to see," said Mark Obrinsky, chief economist at the National Multi Housing Council, a Washington-based trade group. "Many of the cities are committing themselves to regrowth and development, and in newer cities like Dallas we're beginning to see new restaurants, bars and apartments in the downtown areas that put it a bit closer to being a 24-hour city."
He noted that the division between city and suburbs is blurring, too. There's no longer a clear line between an economic center where people work and suburban bedroom communities. Both can be home to major companies and residences.
Census data show that many closer-in suburbs linked to a city with public transit or well-developed roadways are benefiting from strong city growth, while far-flung areas near the metropolitan edge are fizzling after heady growth during the mid-decade housing boom.
Suburbs in the South and West also are seeing some gains, such as those around Houston, Phoenix, Las Vegas and Jacksonville, Fla.
New Orleans, which saw its population shrivel in the mid-2000s after Hurricane Katrina, continued to post the biggest increase in city growth relative to suburbs in the past year - 2.5 percent vs. 0.6 percent. Atlanta, Richmond, Va., Denver, Boston and Charlotte, N.C., also showed wide disparities between city and suburbs.
Other big cities showing faster growth compared with the previous year include Los Angeles, Chicago, Houston, Dallas, Phoenix, San Francisco and Columbus, Ohio.
In all, primary cities in large metropolitan areas with populations of more than 1 million grew by 1.12 percent last year, compared with 0.97 percent in surrounding suburbs. In 2011, the gap between city and suburb growth was narrower - 1.03 percent vs. 0.96 percent.
During the mid-decade housing boom, city growth had come to a standstill, while exurban growth rose by 2 percent, as the wide availability of low-interest mortgages pushed new residential development outward.
"The country has been exposed to a very difficult five years, and many people are reluctant to take chances," said Johnson, the University of New Hampshire demographer. "Marriages are still down, births are still down. Economists may say that the recession is over, but the recovery has not yet been fully reflected in demographic trends."
-New York, Los Angeles, Philadelphia and Boston each grew faster between 2010 and 2012 than they did annually between 2000 and 2010.
-Texas continued to be the big population winner, accounting for eight of the 15 fastest-growing cities with populations of 50,000 or more from 2011-2012.
-New York remained the nation's most populous city, at 8.3 million, with the rest of the top 10 unchanged. Austin, Texas, moved up from 13th to 11th, supplanting Jacksonville, Fla.; Indianapolis slipped from 12th to 13th.