The US counties that diversified most since 2000

In 2000, Forsyth County, Georgia was 92.3% non-Hispanic white. In the 2020-2024 American Community Survey it is 61.8% white, 19.6% Asian, and 10.1% Hispanic. On the CensusEasy diversity score, a 0 to 100 scale where 100 means five racial and ethnic groups of equal size, the county went from 18.1 to 70.7. That is the largest gain among the 613 US counties with at least 100,000 residents.

The score is a Simpson diversity index: the probability that two residents picked at random belong to different groups, using five categories (non-Hispanic white, Black, Hispanic, Asian, and everyone else). A county that is 96% one group scores around 10. Queens County, New York, the most diverse large county in the country, scores 96.2.

The 25 counties that diversified most, 2000 to 2024

Of the 613 counties, 587 became more diverse and 26 became less diverse. The median county gained 17.2 points. Georgia has four of the top 25, Pennsylvania has four, and Arkansas, Minnesota, and Virginia have two each. Every county in the top 25 was at least 76% white in 2000. None is above 80% white now.

The counties near the top share a pattern. They were outer suburbs or small metros in 2000, and most of them roughly doubled in population since. Forsyth grew from 98,407 people to 282,805. Paulding County, on the west side of metro Atlanta, went from 81,678 to 190,996, and its Black share rose from 6.9% to 23.1%. Kendall County, Illinois, southwest of Chicago, went from 54,544 to 145,470 and is now 22.4% Hispanic. Loudoun County, Virginia more than doubled to 449,749 and is now 21.7% Asian.

The exceptions are the Pennsylvania counties. Luzerne County, which includes Wilkes-Barre and Hazleton, added about 13,000 people in 25 years and went from 96.0% white to 74.2%. Its Hispanic share went from 1.2% to 17.3%. Lackawanna County next door, home to Scranton, grew by about 3,000 people over the same period and went from 95.9% white to 79.6%. In those counties the change came from who moved in, not from how many.

Where the change is Black, Asian, or Hispanic

The group driving the change differs by region. In the four Georgia counties and in DeSoto County, Mississippi, outside Memphis, it is mostly Black residents. Henry County, Georgia went from 14.6% Black in 2000 to 51.2% in 2024, and its white share fell from 80.1% to 32.4%. In Loudoun, Collin County, Texas, and Forsyth, it is Asian residents: 21.7%, 18.7%, and 19.6% respectively in 2024, from 5.3%, 6.9%, and 0.8% in 2000. In the Pennsylvania, Arkansas, Illinois, and Florida counties it is Hispanic residents. Lehigh County, Pennsylvania is 28.0% Hispanic, up from 10.2%.

The national figures over the same period: the non-Hispanic white share of the US population went from 69.1% to 57.4%, the Hispanic share from 12.5% to 19.3%, the Asian share from 3.6% to 5.9%, and the Black share stayed near 12%. In 2000, 547 of the 613 large counties had a white majority. Sixty-nine of those have lost it since.

The 10 counties that became less diverse

Twenty-six counties moved the other way. In most of them one group was already the largest in 2000 and kept growing until it dominated the mix. On this index a county that goes from 57% Hispanic to 69% Hispanic scores lower, because two random residents are now more likely to belong to the same group.

Clayton County, Georgia, south of Atlanta, is the one county on this list where the largest group is Black: 51.1% in 2000 and 68.5% now. The other nine are either Hispanic-majority counties along the Texas and California borders and in the Central Valley, or in the case of Sumter County, Florida, home to The Villages, a county that got whiter as it grew.

Gwinnett, Osceola, and Prince William

Three counties CensusEasy has written about before sit lower on this list than readers might expect, because their big shifts happened before 2000. Gwinnett County, Georgia ranks 52nd for change since 2000, from 64.6 to 94.1, but its 2024 score is the fourth highest of any large county in the country, behind Queens, Fort Bend County, Texas, and Solano County, California. Gwinnett was 67.0% white in 2000 and is 30.6% white now, with Black, Hispanic, and Asian shares of 27.8%, 23.7%, and 13.2%. Prince William County, Virginia ranks 102nd for change and 12th for its 2024 score of 92.0. Osceola County, Florida gained only 5.9 points because it went from 29.4% Hispanic to 56.0% Hispanic; the county became majority Hispanic, which on this index counts as one group replacing another rather than as more mixing.

That last case is the limit of the score. It measures how evenly a county's population is split across five groups, not how much the county has changed. A county that goes from all one group to all another group would score the same at both ends. The county pages linked in the tables carry the full breakdown for each year, so the change in any one group can be read directly.