The most basic concept to understand when examining regional migration is the fact that industrialization has always developed unevenly. Because jobs were never on a geographic parity with workers, workers have been forced to pack up and move themselves to areas were jobs were plentiful. Wartime mobilization heightened this phenomenon.

World War I

American industrialists had long exploited the unevenness of worldwide economic development by employing immigrants, many of whom they recruited directly to their factories. By 1915, however, World War I had stopped the flow of immigrant labor. As a result, new opportunities for industrial employment opened for Americans living in rural poverty and for blacks and other minorities in the South. As war orders from England and France rose, and especially after the United States entered the war in 1917 and mobilized...