PLATO, Mo. — In a nation of nearly 310 million people, America's new population center rests not in a Midwestern skyline of St. Louis or Chicago, but in a tiny Missouri village named after an ancient Greek philosopher.

The Census Bureau announced Thursday what the 109 residents of Plato had suspected for weeks: Shifting population patterns and geographical chance converged to make this town on the edge of Mark Twain National Forest the center of the U.S. population distribution based on 2010 census data.

The announcement also signifies larger trends — America's population is marching westward from the Midwest, pulled by migration to the Sun Belt. And in a surprising show of growth, Hispanics now account for more than half of the U.S. population increase over the last decade.

Such designations aren't new to Missouri. The 2000 population center was Edgar Springs, about 30 miles to the northeast. Thirty more miles to the northeast is Steelville, the 1990 population center.

That doesn't mean locals aren't downright thrilled with the recognition and a chance to be noticed.

"It is putting a spotlight on a corner of the world that doesn't get much attention," said Brad Gentry, 48, publisher of the weekly Houston Herald newspaper 30 miles up the road. "Most residents are proud of our region and like the idea that others will learn our story through this recognition."

The Census Bureau's first set of national-level findings from 2010 on race and migration show a decade in which rapid minority growth, aging whites and the housing boom and bust were the predominant themes.

The final count: 196.8 million whites, 37.7 million blacks, 50.5 million Hispanics and 14.5 million Asians.

Hispanics and Asians were the two fastest growing demographic groups, increasing about 42 percent from 2000. Hispanics, now comprise 1 in 6 Americans; among U.S. children, Hispanics are roughly 1 in 4.

More than 9 million Americans checked more than one race category on their 2010 census form, up 32 percent from 2000, a sign of burgeoning multiracial growth in an increasingly minority nation.

Based on the 2010 census results released by state so far, multiracial Americans were on track to increase by more than 25 percent, to roughly 8.7 million.

"This really is a transformational decade for the nation," said William H. Frey, a demographer at the Brookings Institution who has analyzed most of the 2010 data. "The 2010 census shows vividly how these new minorities are both leading growth in the nation's most dynamic regions and stemming decline in others."

For the first time, Asians had a larger numeric gain than African-Americans, who remained the second-largest minority group at roughly 37 million.

The number of non-Hispanic whites, whose median age is now 41, edged up slightly to 197 million. Declining birth rates meant their share of the total U.S. population dropped over the last decade from 69 percent to about 64 percent.

The Census Bureau calculates the mean U.S. population center every 10 years based on its national head count. The center represents the middle point of the nation's population distribution — the geographic point at which the country would balance if each of its 308.7 million residents weighed the same.

Based on current U.S. growth, which is occurring mostly in the South and West, the population center is expected to cross into Arkansas or Oklahoma by the middle of this century.

The last time the U.S. center fell outside the Midwest was 1850, in the eastern territory now known as West Virginia. Its later move to the Midwest bolstered the region as the nation's heartland in the 20th century, central to farming and manufacturing.

But Plato doesn't reflect the population changes that have brought it special attention. The town and its surroundings have few blacks and even fewer Hispanics, though there are more minorities in three or four larger cities about 20 to 30 miles away.

Rumblings of Plato's newfound fame have stirred for weeks, only to be confirmed Tuesday when a pair of census officials came to town to plot the precise midpoint, which is located in a rolling pasture in an area dominated by beef and dairy farms.

A commemorative plaque noting the distinction will be unveiled in April on a monument carved from Missouri red granite, said Elizabeth Frisch, vice president of the local bank. The plaque will be next to the post office, adjacent to the marker noting the town's 1858 founding.

For most in town, it was business as usual Thursday. The sign outside Plato Christian Church offered "Today's forecast: God reigns and the Son shines." Diners at Weber's Cafe enjoyed $3 hamburgers and $5.99 pork chop dinner plates. Students in the entrepreneurial business class at Plato R-V High School hatched ideas to sell T-shirts and other paraphernalia celebrating the town's new distinction.

Despite — or perhaps because of — its isolation, Plato attracts a mix of lifelong locals and those eager to escape the rat race. Frisch, a New Jersey native who moved to central California, discovered the region on cross-country trips to visit family on the East Coast.

She noted that the number of town residents had increased by nearly 50 percent — from 74 to 109 — since the previous census, attributing the growth to military retirees and active-duty military stationed at the sprawling Fort Leonard Woods, 10 miles away.

"We've had a population explosion in 10 years," she joked.

Yen reported from Washington.