The denser the place, the greater the racial integration—or, in other words, cities tend to be more racially diverse while less dense areas generally have higher percentages of white people, according to this chart from Bill Rankin at racialcartography.net. Rankin used 2000 U.S. Census data to graph percentages indicating the existence of racial and ethnic groups based on a place's population density. Each color correlates with a different race, and the accompanying dotted line shows the percentage of the overall population the group accounts for.
As you can see, the blue line for white people exceeds its national total in less dense areas. As you move right for higher densities, the lines for other races move up, signifying greater racial diversity. The exceptions are American Indians and Alaska natives, who largely live in the lowest density areas, as shown by the yellow line. That said, just because there are varying races in an area does not mean it's integrated. Rankin also created this chart to show that in most neighborhoods, one major race or ethnicity tends to dominate, and the second most prominent race in the neighborhood does not come close to matching it:
It's possible that with the jump in Hispanics in America since 2000 the chart would look a little different—that pink line would be higher. The second graph, however, would remain about the same: The country still shows "surprising" segregation.