Large numbers of Black Americans - alongside poor whites - migrated to Chicago, Detroit and St Louis in the early part of the 20th century. They wanted to escape farm labor and get work in factories and service industries.
Blues and jazz migrated to Chicago, too.
Current figures on Race and Ethnicity in the US, acc to Wikipedia -
White Americans (non-Hispanic/Latino and Hispanic/Latino) are the racial majority, with an 80% share of the U.S. population.
Hispanic and Latino Americans compose 15% of the population.[5]
Black Americans are the largest racial minority, composing nearly 13% of the population.[4][6]
White Americans are the majority in every region,[4] and reach their highest share of the population in the Midwestern United States: 85% per the PEP,[4] or 83% per the ACS.[6]
The South is where Blacks and African Americans are most prevalent, as it is home to 55% of the community.[4]