Comparing the Racial Segregation of U.S. Cities

The City Observatory used American Community Survey from the U.S. Census to compare the segregation of the largest U.S. cities. Portland is the most integrated American city; Detroit is the most segregated U.S. city.

2 minute read

August 23, 2020, 11:00 AM PDT

By James Brasuell @CasualBrasuell


Portland Weird

Josh Rainey Photography / Shutterstock

Joe Cortright shares an investigation into the racial segregation of the largest cities in the United States, using a Dissimilarity Index, "which measures the extent to which different groups of people live in different neighborhoods in a city or metro area," built on American Community Survey (ACS) and the previous work of the St. Louis Federal Reserve Bank.

"The index ranges from zero (perfectly integrated, where the composition of each neighborhood matches the composition of the larger region) to one (completely segregated) where each neighborhood consists entirely of persons of a single racial or ethnic group)," explains Cortright of the way the Dissimilarity Index measures segregation.

The tabulation shared by Cortright includes only central counties with populations of 100,000 or more, producing quite a bit of variation, once cities start to deviate from the median. "The median large metro area has a dissimilarity index of 45, meaning that about 45 percent of a city’s population would have to move to balance the composition of individual neighborhoods to the region’s overall demographic composition. About half of all large cities have dissimilarity indices between about 38 and 54," according to Cortright.

When it comes to ranking cities in terms of their relative segregation or integration compared to other U.S. cities, the cities with the highest levels of segregation are Detroit, New Orleans, Philadelphia, Buffalo and Milwaukee, according to Cortright, each with a dissimilarity index exceeding 60.

On the other end of the spectrum, the cities with the lowest levels of segregation are Portland, Virginia Beach, Boston, Seattle and Las Vegas, according to Cortright.

Cortright also notes that the ACS data also allows for segregation to be measured over time. "For most large US metro areas the trend in segregation is downward: Dissimilarity indices are declining over time," according to Cortright.

The article also includes more details about the historic downward trend of segregation in Portland.

Tuesday, August 18, 2020 in City Observatory

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

June 11, 2025 - Diana Ionescu

Metrorail train pulling into newly opened subterranean station in Washington, D.C. with crowd on platform taking photos.

Congressman Proposes Bill to Rename DC Metro “Trump Train”

The Make Autorail Great Again Act would withhold federal funding to the system until the Washington Metropolitan Area Transit Authority (WMATA), rebrands as the Washington Metropolitan Authority for Greater Access (WMAGA).

June 2, 2025 - The Hill

Large crowd on street in San Francisco, California during Oktoberfest festival.

The Simple Legislative Tool Transforming Vacant Downtowns

In California, Michigan and Georgia, an easy win is bringing dollars — and delight — back to city centers.

June 2, 2025 - Robbie Silver

Street scene in Kathmandu, Nepal with yellow minibuses and other traffic.

The Small South Asian Republic Going all in on EVs

Thanks to one simple policy change less than five years ago, 65% of new cars in this Himalayan country are now electric.

45 minutes ago - Fast Company

Bike lane in Washington D.C. protected by low concrete barriers.

DC Backpedals on Bike Lane Protection, Swaps Barriers for Paint

Citing aesthetic concerns, the city is removing the concrete barriers and flexposts that once separated Arizona Avenue cyclists from motor vehicles.

2 hours ago - The Washington Post

Bird's eye view of studio apartment design.

In These Cities, Most New Housing is Under 441 Square Feet

With loosened restrictions on “micro-housing,” tiny units now make up as much as 66% of newly constructed housing.

4 hours ago - Smart Cities Dive