A doorman walks under an awning of a residential building on Park Avenue in New York.

Some of the largest housing markets in the United States also happen to be the most racially segregated, according to a study released Thursday.

Online rental marketplace Apartment List found "significant patterns of residential segregation" among major areas — even though many of those places enjoy reputations as cultural "melting pots."

Milwaukee, New York, Chicago, St. Louis and Cleveland round out Apartment List's five most-segregated housing markets — with places like Los Angeles, Philadelphia and Washington also ranking high on the list.

The segregation effect is most pronounced in cities like New York, where affordable housing is particularly scarce. A recent study commissioned by New York City Councilman Brad Lander found the Big Apple was "more segregated than most metropolitan areas in the United States."

"Although this year represents the 50th anniversary of the Fair Housing Act, we still have a long way to go to ensure that equality of opportunity is not negatively impacted by the neighborhood in which a person is raised," wrote Chris Salviati, Apartment List's housing economist. He analyzed Census figures and its own data compiled from 66 million users in more than 40 cities.

"The presence of residentially segregated neighborhoods affects all minority groups, but the issue is most extreme for black households," Salviati said. "Black populations are the most segregated minority group in all of the nation's 25 largest metros except for Phoenix, where the Hispanic segregation index is highest."

The racial divide in major cities also tends to exacerbate gaps in homeownership between white and nonwhite households, Apartment List's data showed, with some of the fastest growing populations seeing relatively high levels of segregation.

"Across the U.S., 72.4 percent of white households own homes, compared to 57.3 percent of Asian households, 48.4 percent of Hispanic households, and just 42.2 percent of black households," Apartment List's study found. "These gaps in homeownership rates vary by metro, and we find that higher levels of residential segregation are correlated with more severe homeownership rate gaps."