By Jens Manuel Krogstad

In the United States as a whole, the white share of the population is declining as Hispanic, Asian and black populations grow. But the shift to a more diverse nation is happening more quickly in some places than in others.

From 2000 to 2013, 78 counties in 19 states, from California to Kansas to North Carolina, flipped from majority white to counties where no single racial or ethnic group is a majority, according to a new Pew Research Center analysis of Census Bureau data. (Our analysis includes only counties with a minimum population of 10,000 in 2013.)

Overall, 266 of these 2,440 counties are less than half white. However, many are in urban areas that together account for about one-third (31%) of the nation’s population, despite making up just 11% of U.S. counties with a minimum population of 10,000. These counties are concentrated in California, the South and the East Coast, bypassing much of the country’s middle section.

In 19 of the 25 biggest U.S. counties by population, whites make up less than half of the population. Of these, six that were majority white in 2000 are no longer so: San Diego, Orange, Riverside and Sacramento counties (all in California), plus Clark County, Nev., and Broward County, Fla. In addition, whites could soon become the minority in two more counties – Tarrant in Texas (Fort Worth) and Wayne in Michigan (Detroit), both of which are now 50% white.

Read More Reflecting a racial shift, 78 counties turned majority-minority since 2000 | Pew Research Center.