In some cities, this evolution may take some time, as many communities tend to self-segregate—even if they don’t mean to. But in others, the racial and ethnic makeup of the city that may have defined it a mere 30 years ago has completely changed, and will continue to do so.
Using historical data from The National Historical Geographic Information System (NHGIS) and the United States Census, MooseRoots created a “Diversity Index” to see which cities in America have become the most racially diverse from 1970 to 2010.
To do so, they took the four race classifications from the census: White, Black or African-American, American Indian and Alaska Native, Asian and Pacific Islander, and Other Race. They didn’t include multi-racial individuals because the census only began tracking multi-racial demographics in 2000. MooseRoots deemed the most diverse places those where racial makeup approached an even distribution between the four classifications.
Changing Demographics
In 1870, nearly 100% of people living in Arizona identified themselves as white. This state went from being almost entirely white in 1870 to having a sizable non-white population of 22% by 2010. One reason for this is the growth of the Native American population, which now comprises 4% of the population.
By 2010, the proportion of people who identified as non-white in Arizona was roughly 81 times larger than it was in 1870.
Growing Hispanic Population
The Hispanic population in Arizona grew from 15% in 1970 to 29% in 2010.
The Census Bureau defines 'Hispanic or Latino' as someone who classified his or herself as Cuban, Mexican, or Puerto Rican, or someone whose origins are from Spain, the Spanish-speaking countries of South or Central America, or the Dominican Republic. This classification is independent from the person's race.
By 2010, Arizona's foreign-born population was roughly 150 times larger than it was in 1870, surging from 5,809 people in 1870 to 868,819 people in 2010. However, the percentage of the foreign born population decreased from 60% to 14%.
Note: Data is not available for 1960.

