The Great Migration generally refers to the massive internal migration of Blacks from the South to urban centers in other parts of the country. Between 1910 and 1970, an estimated 6 million Blacks left the South. This graphic compares an early wave of migration (1910-1940), sometimes referred to as the First Great Migration, with a later wave of migration (1940-1970) also known as the Second Great Migration.

NOTE: Data are from decennial censuses, 1910 through 1970. Population counts are based on unrevised numbers. Data for the Black population for cities in Alaska and Hawaii were not available in 1940 or earlier decades. Cities shown are those that were either in the top 100 cities in the country or top 3 of a state and had a Black population of at least 100 people. These criteria were placed on 1940 data for the First Great Migration and 1970 data for the Second Great Migration.