Definition
The Great Migration is the relocation of approximately six million Black Americans from the rural and small-town South to the urban North, Midwest, and West between roughly 1915 and 1970.
It is the largest internal migration in U.S. history measured by share of a population affected: by 1970, only about half of Black Americans still lived in the South, down from nearly 90% in 1910. The movement reshaped the demography of cities, the geography of race, the labor force of Northern industry, and the political alignments of both regions. Historians treat it less as a single event than as a sustained six-decade exodus driven by Jim Crow violence, agricultural collapse, and Northern wartime labor demand.
Why it matters
How it works
The migration unfolded in three waves with distinct triggers. The first wave (1915–1929) was pulled by Northern factory demand during World War I when European immigration was cut off, and pushed by the boll weevil's destruction of Southern cotton. Black newspapers like the Chicago Defender circulated through the South via Pullman porters, advertising jobs and routes. The second wave (1940–1950) rode wartime industrial mobilization for World War II. The third wave (1950–1970) was the longest and most diffuse, driven by mechanized cotton harvesting that eliminated millions of sharecropping livelihoods and by accumulated chain-migration networks pulling kin along established corridors.
Three rail lines became the migration's spine. The Illinois Central carried Mississippi Delta migrants north through Memphis to Chicago, Milwaukee, and Detroit. East Coast lines moved Carolinas, Georgia, and Florida migrants up to Washington, Philadelphia, New York, and Boston. The Southern Pacific's Sunset Limited carried Louisiana and East Texas migrants west to Los Angeles and Oakland. The corridor a migrant chose largely depended on where in the South they started — Wilkerson's three protagonists each followed one of the three.
What the migrants found in the North was not the promised land. Housing covenants confined them to overcrowded "Black Belts," redlining starved their neighborhoods of credit, and Northern unions often barred them from skilled trades. But wages were higher, schools were better, the vote was real, and lynching was rare. The cumulative effect over decades was the urbanization of Black America and the transformation of cities like Chicago, Detroit, and Harlem into centers of Black culture, politics, and economic life.