The unemployment rate for black Americans fell below 6.0% for the first time in history earlier this year. The historic dip in joblessness was a benchmark of progress in the continued pursuit of racial equality in the United States — and a reminder of the unique challenges black Americans face every day.

The black unemployment rate has hovered above the overall unemployment rate by several percentage points since the Bureau of Labor Statistics began tracking it over 40 years ago. Racial disparities in America do not stop with the labor market.

The median annual income among black households in the United States is just $36,651, about $24,000 shy of the median income among white households. Black Americans are also less likely to own a home, less likely to have a college education, and five times more likely to be incarcerated than white Americans.

Click here to see the worst cities for black Americans.

Disparities in socioeconomic measures exist to some degree nationwide. However, in certain cities, gaps in outcomes along racial lines are chasmic. 24/7 Wall St. created an index based on racial disparities in eight socioeconomic measures in U.S. metro areas to identify the worst cities for black Americans.

In an interview with 24/7 Wall St., Camille M. Busette, a senior fellow at the Brookings Institution, laid out some of the causal factors behind these disparities in the cities on this list. “Looking historically, these are cities where there is a tremendous amount of residential segregation,” Busette said.

The cities on this list are largely concentrated in the Midwest and have long histories of systemic racial segregation. Though about half a century has passed since the Fair Housing Act legally banned discriminatory lending, zoning, and renting practices, such practices persist in much of the country in less overt ways.

Busette described the day-to-day implications of segregation. “People are not walking around, working together, going to school together, taking the same metro together, et cetera. So there isn’t a lot of familiarity.”

This kind of segregation can have profound consequences for labor markets. “People tend to hire people like themselves, so when you get residential segregation, you tend to also get employment segregation,” Busette said.

Segregation serves to perpetuate inequality in other ways as well. “Where you have residential segregation and where you have large percentages of poor black populations, the schools that service those neighborhoods tend to be substandard relative to white neighborhoods,” Busette said.

Second-rate schools in black neighborhoods in many of the cities on this list result in lower educational attainment rates — which in turn contribute to disparities in other measures like income, unemployment, and incarceration.

Methodology

To determine the 15 worst cities for black Americans, 24/7 Wall St. created an index consisting of eight measures to assess race-based gaps in socioeconomic outcomes in each of the nation’s metropolitan areas. Creating the index in this way ensured that cities were ranked on the differences between black and white residents and not on absolute levels of socioeconomic development. For each measure, we constructed an index from the gaps between black and white Americans. The index was standardized using interdecile normalization so outliers in the data did not skew results. We excluded metro areas where black residents comprised less than 5% of the population or where data limitations made comparisons between racial groups impossible.

Within the index, we considered 2016 data from the U.S. Census Bureau’s American Community Survey on median household income, poverty, adult high school and bachelor’s degree attainment, homeownership, and unemployment rates. All ACS data are five-year estimates. Data on incarceration rates came from The Sentencing Project, a nonprofit dedicated to criminal justice reform, and are for the most recent available year. Because states, rather than metro areas, are responsible for the prison population, incarceration rates are for the state where the metro area is located. If a metro area spans more than one state, we used the state in which the metro area’s principal city is located. From the Centers for Disease Control and Prevention, we used age-adjusted mortality rates by race for each U.S. county from 2012-2016 to calculate mortality rates at the metro level using a variation on the indirect standardization method. Incarceration and mortality rates are per 100,000 residents.