ASHINGTON, June 4 — Despite the surging economy of the 1990's that brought affluence to many Americans, the poor remained entrenched, the Census Bureau reported today. The bureau's statistics for the 50 states and the District of Columbia show that 9.2 percent of families were deemed poor in 2000, a slight improvement from 10 percent in 1989.

Men's incomes fell in 26 states. Nationally, their median incomes — meaning half earned less and half more — fell 2.3 percent. Women's incomes, while 73 percent of men's, rose 7 percent over all and increased in every state except Alaska. More women than ever went to work.

"Some people thought you lost if you didn't do as well as the next guy," said Martha Farnsworth Riche, a demographer and former director of the Census Bureau. "There's no doubt that we saw more inequality in the 1990's, but people won across the board in a variety of ways."

The data released today provide the first national look from the 2000 census at such demographic issues as income, poverty, occupation, housing and the percentage of foreign-born people living in the United States. The data are compiled from the 53-question form that was distributed to about 19 million, or about 1 in 6, of the country's households in the spring of 2000. Thus it picked up none of the impact of the recession that was beginning then.

Expanding upon figures from the initial 2000 census reports last year, the bureau reported that more than half the foreign-born population — 52 percent — came from Latin America, an increase from 44 percent in the decade. Of the 281.4 million people the census found in 2000, it said 31.1 million came from abroad, 11.3 million more than in 1990, an increase of 57 percent.

This increase in the immigrant population, which many state officials believe was undercounted, surpassed the century's greatest wave of immigration, from 1900 to 1910, when the number of foreign-born residents grew by 31 percent, according to the Center for Immigration Studies in Washington.

Demographers noted that for the first time in the 1990's, immigrants moved far beyond the big coastal cities and Chicago and Denver and Houston, into the Great Plains, the South and Appalachia.

The foreign-born population of Franklin County, Ala., grew from 0.19 percent to 5.55 percent, or from 79 people to 1,734. Dawson County, Neb., had 3,866 foreign residents, or 16 percent of the population, in 2000, up from 138 people in 1990.

"These numbers represent an enormous social experiment with very high stakes," said Steven A. Camarota, director of research for the Center for Immigration Studies, which advocates stricter immigration control. "No country has ever attempted to assimilate and incorporate 31 million newcomers, and the experiment is not over."

Other analysts add, however, that immigrants helped propel the boom in the 90's, taking low-paid service jobs and vital assignments in medicine and in technology companies.

Reynolds Farley, demographer at the University of Michigan, said some of the nation's old, ailing cities also had low growth of both industry and immigration.

Much of the huge growth in immigration in Sun Belt states, including Nevada, Arizona, Georgia, North Carolina and Tennessee, was fueled by growth in domestic migration. The flow of wealthy individuals fleeing congested big cities created the need for low-wage workers to build homes, staff restaurants and hotels and do other low-paid service work. The result is a barbell economy of extreme haves and have-nots, said William Frey, a demographer with the Milken Institute, an economic research group in Santa Monica, Calif.

Nevada, for instance, had a 94 percent increase in the number of people with professional and graduate degrees, but also a 76 percent increase of people with less than a ninth-grade education, a number driven by new immigrants. "In the short term these groups complement one another," Mr. Frey said. "But over the long term there will need to be significant investment at the local and state level to bring these immigrants and their children into the middle class."

The census data also indicated that sprawl intruded upon the ways Americans lived and worked. Commuters spent an average of 25.5 minutes getting to work in 2000, about 3 minutes more than in 1990. Fewer walked or took public transportation. More chose to avoid all commuting. In 2000, 3.3 million people worked at home, 23 percent more than at the beginning of the decade.

The surging economy was a boon to many.

In 10 years, owners saw the value of their homes rise 17 percent, to a median $119,600, after barely budging in the 1980's. But there were signs that new and typically bigger houses were becoming harder to hold. For 15.8 percent of homeowners, mortgage and maintenance costs exceeded 35 percent of household income, an increase from 13.5 percent in 1990.

"Americans have more wealth, but they're living in it," Ms. Riche said. "With less liquid wealth, there's less flexibility" to save money for retirement or college tuitions.

While not all the same people were poor at the end of the decade as at the start, the proportions of the poor changed little. About 6.6 million families, or 9.2 percent of all families, qualified as poor in 1999, down from 10 percent in 1989. In 1999, a family of four was said to be living in poverty if its income was less than $16,954.

Poverty from state to state and county to county varied widely. The Children's Fund, a liberal advocacy organization, said the census showed that in nine states and the District of Columbia, one in five children was poor. "The goal is to help families escape poverty, not just escape from the welfare rolls," said Marian Wright Edelman, the organization's president.

Poverty among adults declined little, too, from 11.3 percent to 10.9 percent. But with the overhaul of the welfare system six years ago, many women with children left the welfare rolls for work.

The poverty rate among female-headed households with children younger than 18 fell from 42.3 percent to 34.3 percent. Poverty among the elderly also declined, to 9.9 percent of people older than 65 from 12.8 percent.

Still, American families realized some solid gains in the decade. After taking inflation into account, the bureau found that the median family income climbed 9.5 percent from 1989 to 1999, to $50,046.