Final answer:
Harlem and industrial Midwest/Northeast cities had high concentrations of Black residents due to historical factors and segregation laws.
Explanation:
Harlem in New York City had the greatest concentration of Black residents in the early 1900s during the Great Migration, with its population growing significantly.
Residential segregation was prevalent in both Southern and Northern cities, with African Americans living in distinct neighborhoods due to discriminatory practices and laws.
City neighborhoods in the Industrial Midwest and Northeast, such as Cleveland, Detroit, Chicago, and Milwaukee, had high concentrations of Black residents by the 1980s, showcasing extreme segregation index scores.
Learn more about Black residential concentration in US cities here:
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