U.S. underwent a population boom in the '90s

Fueled by a steady birthrate, greater longevity and explosive immigration, the nation's population increased by more people in the 1990s than any other 10-year period in U.S. history, the Census Bureau reported Monday.

More than 281-million people called America home in 2000, an increase of 13 percent, or nearly 32.7-million, from 1990. That easily surpassed the previous record growth of 28-million during the peak of the 1950s baby boom.

Even as many industrial countries are suffering declining populations because of shrinking birthrates, the U.S. population swelled as a result of new waves of young immigrants with families and a steady birthrate that outpaced deaths.

To put the increase in perspective: It is 1-million people larger than the combined 2000 head count of the 19 least-populated states and the District of Columbia. It is also 6-million more than the entire U.S. population in 1860.

The 13.2 percent population increase during the 1990s does not represent the fastest growth rate; the 1950s posted an 18.4 percent increase. The population grew at least 15 percent during the first three decades of the 20th century.

Still, the 1990s represent a dramatic turnaround from census predictions in the late 1980s that the U.S. population would level off and then decline in the 21st century.

"That's no longer true," said Steve Murdock, director of the Texas State Data Center. More recent projections, he said, suggest that the nation will have a population above 500-million by the end of this century.

The growth in the 1990s was notable for not only its size, but also its breadth. For the only time in the 20th century, the population of all 50 states increased, ranging from a tiny half-percent rise in North Dakota to the booming 66 percent in Nevada. Eighty percent of the nation's 3,141 counties and equivalent areas grew, compared with 55 percent in the 1980s.

The nation grew faster and in more corners of the country than the Census Bureau had projected. The number of people in metropolitan areas grew by 14 percent in the past decade, narrowly exceeding non-metropolitan counties, which grew by 10 percent. Four out of five Americans, however, still live in cities or suburbs.

Eight of the 10 largest cities gained population in the 1990s, with only Philadelphia and Detroit shrinking in size. New York, Los Angeles and Chicago remained the top three metropolises. But in a sign of the Sun Belt's pull on Americans and immigrants, Houston, Phoenix and San Diego were three of the next four largest cities.

The fastest-growing metropolitan area was Las Vegas, whose population jumped 710,000 or 83 percent during the 1990s. The second-fastest-growing was Naples, Fla., which gained 65.3 percent to 251,377 residents.

The fastest-growing region was the West: up 19.7 percent to 63.2-million. The population of the Midwest rose 7.9 percent to 64.4-million, and the Northeast grew by 5.5 percent, to 53.6-million.

The South gained 14.8-million people in the 1990s, a 17 percent increase, and is now home to 100.2-million Americans.

In the South, Georgia grew fastest: 26 percent.

It was the first decade of this century that Florida was not the South's fastest-growing state, said Marc Perry, a Census Bureau demographer. However, Texas and Florida posted the largest numeric increases of all Southern states, adding 3.9-million and 3-million respectively.

As a result, the geographic center of country, as calculated by the Census Bureau, moved to Edgar Springs, Mo. The population center is determined as the place where an imaginary, flat, weightless map of the United States would balance perfectly if all 281.4-million Americans were of identical weight. Edgar Springs claimed the title from Steelville, about 40 miles to the northeast in Crawford County. With each census the center point has been shifting west, having entered Missouri at De Soto in 1980.

The trends emerging from the Census 2000 head count include the convergence of two major demographic patterns. Sprawl from metropolitan areas accelerated through the 1990s, spilling into once rural areas and stemming decades-long population declines in many non-metropolitan counties.

"A lot of growth in non-metropolitan areas in the last decade has come in counties that adjoin metropolitan areas and is changing the character of those counties," said Calvin L. Beale, a senior demographer at the Agriculture Department, who has analyzed population shifts in non-metropolitan counties.

Many of these counties are likely to be incorporated into metropolitan regions when the White House's Office of Management and Budget formally reclassifies regions in 2003, census officials and outside demographers said.

More than half of the 1990s' population increase was due to births surpassing deaths, said John Long, chief of the Census Bureau's population division. The U.S. fertility rate held at about 2 children per adult woman.

Immigration, mainly from Asia, the Caribbean and South America, accounted for at least one-third of the population increase, Long said, and increased longevity much of the rest. The impact of immigration, because it includes undocumented illegal immigrants, is hard to measure, experts said.

The Census Bureau's improved counting, particularly of minorities and their children, is another factor in the apparent record growth of the U.S. population to 283-million, Long said.

_ Information from the New York Times, Knight Ridder Newspapers, Dallas Morning News and Associated Press was used in this report.