1920s and '30s: The numbers of unemployed African-Americans during the Great Depression was as much as 25% In northern cities, and well over 50% in many southern cities, figures that were three to four times higher than the number of unemployed whites.

Today: Unemployment among African-Americans averages between 10 and 11 %, higher than the 4 5 to 5% among whites.

1920s and '30s: Blues and jazz flourished from New Orleans to Harlem. Although these indigenous American music forms were the dominant mode of expression for the oppressed black culture, they also attracted a large audience of whites.

Today: Rap and hip-hop are the major musical forms that express the unique experiences of black culture In America's ghettos, but they also have many non-black fans, not only in America, but allover the world.

1920s and '30s: In the South, Jim Crow laws dictated that blacks and whites use separate...