Definition
A labor shortage in this context is the gap between the number of workers Northern industries needed and the number they could hire from existing local and immigrant labor pools — the gap that, during the two world wars, pulled millions of Black workers out of the South and into the factories, packinghouses, shipyards, and steel mills of the North and Midwest.
Two periods dominated. The WWI shortage (1914–1918) followed the collapse of European immigration in August 1914 and the conscription of millions of men into the U.S. military after 1917. The WWII shortage (1941–1945) was deeper still — 12 million Americans in uniform, war production at unprecedented scale, and the same immigration channels closed since 1924.
Why it matters
How it works
The First World War shortage was sudden and severe. Roughly 25 million immigrants had entered the United States between 1880 and 1914; that flow stopped almost overnight when the war broke out in Europe. Industrial production simultaneously expanded to meet war contracts. After the United States entered the war in April 1917, four million more men were taken out of the civilian workforce. Northern industry needed labor and turned for the first time at scale to the Black workforce of the South.
The recruitment was active and visible. The Chicago Defender, the most influential Black newspaper of the era, ran columns urging Southern Black workers to come North. Pennsylvania Railroad and the Illinois Central put labor agents on station platforms in Mississippi and Alabama, paying for tickets. By 1920, the Black population of Chicago had grown from 44,000 to 109,000; Detroit's from 5,700 to 41,000; New York's from 91,000 to 152,000.
The Second World War shortage was longer and structurally different. Roosevelt's Executive Order 8802 (June 25, 1941), issued under pressure from a threatened March on Washington led by A. Philip Randolph, prohibited racial discrimination in defense employment and created the Fair Employment Practices Committee. The order opened — partially and unevenly — the war industries to Black workers. Los Angeles's aircraft plants, Oakland's shipyards, Detroit's converted auto factories absorbed hundreds of thousands of migrants from the rural South.
The pattern Wilkerson emphasizes is the inversion of the standard story. The South did not "push" the migration so much as the North "pulled" it — the structural racism of the South was a constant; what changed in 1915 and again in 1941 was that the Northern labor market opened. When it opened, Black workers came; when it closed, they got laid off, but most stayed.