Final answer:
Since 1860, the African-American population increased in regions outside the South, particularly during the Great Migration, where they moved to Northeastern and Upper Midwestern cities. Subsequent demographic changes also saw an increased presence in Northern and West Coast cities during World War II.
Step-by-step explanation:
The African-American population in the United States experienced significant shifts since 1860. Initially concentrated in the South, African Americans were primarily found in regions such as Delaware, Maryland, Virginia, North Carolina, and later Kentucky, Missouri, Tennessee, and the District of Columbia. During the period after the Civil War, particularly the Great Migration from 1910 to the onset of the Great Depression, nearly two million African Americans left the rural South.
The primary destinations for these migrants were cities in the Northeast and Upper Midwest, such as New York, Chicago, Philadelphia, St. Louis, Detroit, Pittsburgh, Cleveland, and Indianapolis. Later migrations during World War II and the growth of industries further reinforced the increased African-American presence in northern and West Coast cities.