America’s white population declined for the first time while US metro areas were responsible for almost all of the country’s population growth, according to groundbreaking new data released on Thursday by the US census bureau.

Overall, the white-alone population fell by 8.6% since 2010, the bureau said on Thursday. Non-hispanic whites now account for around 58% of America’s population, a drop from 2010 when they made up 63.7% of the population. It was the first time that the non-Hispanic white population has fallen below 60% since the census began.

Meanwhile, there was significant growth among minority groups over the last decade. The Hispanic or Latino population grew by 23%, while the Asian alone population surged by over 35%. The Black population also increased by more than 5.6%.

“The US population is much more multiracial and much more racially and ethnically diverse than we have measured in the past,” said Nicholas Jones, a Census Bureau official.

The data underscores what’s at stake as lawmakers begin the process of drawing political maps that will be in place for the next decade. Relying on the data released Thursday, lawmakers across the country will carve up the 435 districts in the US House of Representatives as well as state and legislative districts.

Just as they did in 2010, Republicans are once again poised to dominate that process and will likely use that advantage to draw districts that will heavily advantage GOP candidates. Those maps could dilute the political voice of the same minority voters who are driving US population growth.

The most diverse states in America, as measured by the bureau’s diversity index, were Hawaii, California, Nevada, Texas, Maryland, the District of Columbia, New Jersey and New York. In Texas, the white and Hispanic or Latino population are getting much closer. Whites made up 39.7% of the population, while Hispanics and Latinos made up 39.3%. The bureau also said there was a sharp spike in the number of people who identified as multiracial.

“Our analysis of the 2020 census show that the US population is much more multiracial and more racially and ethnically diverse than what we measured in the past,” said Nicholas Jones, the director and senior adviser of race and ethnic research and outreach, in the census bureau’s population division.

Overall, America’s population grew 7.4% over the last decade, the second slowest growth in US history. By comparison, the US population grew 9.7% between 2000 and 2010.

Metro areas across the country were responsible for nearly all of that growth, said Marc Perry, a senior demographer at the bureau. “On average, smaller counties tended to lose population and the more populous counties tended to grow,” he said.

Americans continued to migrate to the south and west at the expense of the midwest and north-east, the figures showed.

The fastest growing of America’s largest cities was Phoenix, whose population increased by 11.2% over the last decade. The Arizona city overtook Philadelphia to become the fifth largest city in America. The largest city in America remains New York City, which grew to have 8.8 million people, a 7.7% increase from the last decade.

“Many counties within metro areas saw growth, especially those in the south and west. However, as we’ve been seeing in our annual population estimates, our nation is growing slower than it used to,” Perry said. “This decline is evident at the local level where around 52% of the counties in the United States saw their 2020 census populations decrease from their 2010 census populations.”