As longtime residents of Gina Ryan's middle-class neighborhood in St. Louis moved out, new faces from all over the globe — Mexico, the Philippines, Vietnam — moved in to claim their stake in the American dream.

It is a reflection of the changing face of America's cities, and the challenges municipal leaders face in meeting the needs of their newest residents.

The 2000 census showed Hispanic and Asian populations were the fastest growing groups in the country, while whites continued a years-long trend of leaving cities. Many urban centers also lost black population, though to a lesser extent.

It is unclear exactly how many of those city dwellers who left went to the suburbs; migration data from the 2000 census is not expected until at least this winter. But it is safe to assume that is the route taken by most of those who moved, said Alan Berube, a senior research analyst at the Brookings Institution.

In the nation's 10 most populous cities, the percentage of people in the 2000 census who classified themselves as "non-Hispanic white," not accounting for those who checked off more than one race, was 35 percent. It was down from 43 percent in 1990.

Take Ryan's neighborhood, for example. Though recent studies show St. Louis to have one of the highest rates of black-white segregation in the nation, Ryan's neighborhood has become one of the most diverse in the city.

"It has become a lot more stable, and a lot more integrated neighborhood in the 20 years I've been here" said Ryan, executive director of the St. Louis Association of Community Organizations. "The greatest influx in the last couple years have been people of all races."

While whites continued to leave cities, the urban Hispanic population soared, growing 36 percent in the top 10 cities. The non-Hispanic black population increased slightly in the same cities, by 2 percent.

More Asians also are moving into cities, though direct comparison was not immediately available because of a change in the way the Asian category was presented between 1990 and 2000.

Cities that took the biggest overall population hits were in the older, industrial Northeast and Midwest, though most declines were not as large as forecast.

St. Louis' population decreased 12 percent, one of the steepest drops in the country for a city over 100,000. Its non-Hispanic white population fell by about 25 percent and its black population was down roughly 6 percent. The Hispanic population rose by 37 percent.

The country's most populous city, New York, grew by 9 percent, to more than 8 million. Non-Hispanic whites declined by about 11 percent, non-Hispanic blacks increased at least 6 percent, while the Hispanic population gained 21 percent.

The implications are numerous: Can cities keep up with the unique needs of their newest residents? Can the quality of schools be improved? How will it change the dynamics in local politics?

Undoubtedly, many families of various races moved out of cities after watching people of other races move in. Recent studies have found that segregation remains a serious problem in America's metropolitan areas, though levels decreased slightly in most cities.

But not all big cities had an exodus of white families.

Las Vegas, Austin, Texas, and Charlotte, N.C., for example, all posted gains in minority and white population.

All three have good economies and have become more integrated the past decade, typical of other boom towns in the South and West, said Jacob Vigdor, an assistant professor of public policy studies at Duke University.

Vigdor said it has a lot to do with new neighborhoods and developments sprouting in these towns. Most residents in these neighborhoods are new to the area, so there is more openness and less hesitation between different groups.

Plus, in fast-growing places like Las Vegas, "you have to put people somewhere," he said.

David Wexler, a New York City lawyer, agrees. But his priorities are changing. He is getting married and wants to have a family, so he is trading in his midtown apartment for a home in Westchester County.

"Diversity is important, but it isn't that big an issue for me," Wexler said. "I'm thinking in terms of a nice area to raise a family, good schools, and having a big backyard."

While economic growth is a big attractor for people of all races when figuring out where to move, "there are some things you can't change, like the weather," Berube said. "Quality of life is a big lure these days."