Hispanics have surged past blacks and now constitute the largest minority group in the United States, a status Latino leaders are sure to use to push for political and economic advances.

The Census Bureau released estimates Tuesday showing the Hispanic population rose 4.7 percent between April 2000 and July 2001, from 35.3 million to 37 million. During the same period, the non-Hispanic black population rose about 2 percent, from 35.5 million to 36.1 million.

"This is the first time that Hispanic number surpassed the black number," Census Bureau analyst Roberto Ramirez said Tuesday.

The data are part of the bureau's first statistics on race and ethnicity since results from the 2000 census were released nearly two years ago.

"This undoubtedly is a benchmark with powerful symbolic value," said Roberto Suro, director of the Pew Hispanic Center, a research group. "But it doesn't automatically translate into any tangible benefits for Latinos."

Due to high birth and immigration rates, the Hispanic population more than doubled during the 1990s, the 2000 census found. Many new arrivals were drawn by the booming U.S. economy and settled in areas in the South and Midwest that previously attracted few Latinos.

Democrats and Republicans, aware of the surge, have placed increased emphasis on attracting Hispanic voters.

Last year, the two top Democratic candidates for governor of Texas debated in Spanish. Also last year, the Republican National Committee began sending representatives to citizenship ceremonies to register Hispanic immigrants.

Cecilia Munoz, vice president at the National Council of La Raza, a Hispanic advocacy group, said politicians must do more than ask for support.

"The question is what they intend to do with that," she said. "Are they just going to offer platitudes in Spanish, or offer real public policy suggestions?"

Whites remain the largest single population group, numbering 199.3 million in July 2001, or nearly 70 percent of all U.S. residents, according to the Census Bureau.

Hispanics comprise 13 percent of the U.S. population, which grew to 284.8 million in July 2001. That's up from 35.3 million, or 12.5 percent of the country's 281.4 million residents in April 2000.

Blacks make up 12.7 percent of the population, up from 12.6 percent in April 2000. Asians are the next-largest minority group, at about 12.1 million, or 4 percent of U.S. residents.

Demographers have long forecast that Hispanics would surpass blacks because their birth and immigration rates are higher. Still, tabulating the population data by race and ethnicity is something of an inexact science because of the way the government categorizes people.

The process became even more confusing in 2000 after the Census Bureau allowed people to identify themselves by more than one race.

Hispanic refers to ethnicity rather than race, according to the government. The census form asks people to identify themselves by race and to say whether they are Hispanic or non-Hispanic.

About 1.1 million people in July 2001 were identified by the government as black and Hispanic, while 34.5 million said they were white and Hispanic.

The figure of 36.1 million blacks refers to those who are not Hispanic, just as the figure of 199.3 million whites does not include those who identified themselves as Hispanic and white.

The Associated Press has used the non-Hispanic population figures for blacks and whites since data from the 2000 census was released in April 2001.

Also Tuesday, the bureau released population estimates broken down by age. It found that the median age of the U.S. population -- the point at which half the population is younger and the other half older -- rose from 35.3 to 35.6.