Southerners were not only pushed out of the South, they were also pulled to the North and West by the particular economic climate created by World War II. Indeed, although black tenant farmers and sharecroppers had migrated to Southern cities and towns in the late 1930s, there was no significant movement out of the region during that time. The net African-American migration from the South during the 1930s was only 347,500, scarcely more than a fifth of what it would be in the following decade. The 1940s movement was driven in part by the tremendous expansion of industrial production during and after the war.

Industrial mobilization began even before America's entry into the war in 1941 following the attack on Pearl Harbor. Once the United States became engaged in a two-front war against Japan and Germany, production shifted into high gear. In addition to the usual needs for munitions, clothing, food, and training facilities, the naval war with Japan spurred increased shipbuilding and the production of naval materiel, much of it channeled to and through Pacific coast ports.

	Special Problems of Negro Migration During the War from Postwar Problems of Migration by Ira De. A. Reid
	The Search For Housing , Chapter III from Some Aspects of the Migration of the Negro to the San Francisco Bay Area Since 1940 by Edward Everett France

West Coast aircraft plants increased their work force almost fifteenfold; in 1940 they employed 36,850 workers, but by 1945, on V-J Day, nearly 475,000 were working on the assembly lines. Although Pacific Coast shipyards accounted for more than half of all vessels built during the war, the South, long a major training ground for military forces and the site of numerous bases, also began to produce armaments and warships. Production at Southern textile factories, oil refineries, steel mills, and seaports was also boosted by the war. But even this substantial improvement in the region's economy could not stem the tide of black emigrants.

Black Migration from The Second Gold Rush: Oakland and the East Bay in World War II by Marilynn S. Johnson

Although African Americans were hardly welcomed with open arms in Northern and Western industrial centers, the South was even more deeply racist and hostile. For example, when Bell Aircraft opened a huge factory on the outskirts of Atlanta, it employed 35,000 workers, only 2,500 of whom were black. Of those 2,500, just 800 had skilled positions; the majority were relegated to jobs as janitors, cafeteria workers, and other industrial equivalents of domestic labor. In the Western shipyards, by contrast, men and women in greater numbers could find skilled work.

	African American Militancy in the World War II South: Another Perspective from Remaking Dixie: The Impact of World War II on the American South by Harvard Sitkoff
	Juanita Tucker from Bridges of Memory: Chicago's First Wave of Black Migration by Timuel Black
	Alvin ‘Al’ Boutte: Businessman and Banker from Bridges of Memory: Chicago's First Wave of Black Migration by Timuel D. Black

Friends and family members who had already made the trip north or west and had found better jobs than the South had to offer enticed those who had not yet moved to follow them. Letters were sent back home with descriptions of the riches that could be found above the Mason-Dixon Line:

Hello Dr., my dear old friend. These moments I thought I would write you a few facts of the present conditions in the North. People are coming here every day and finding employment. Nothing here but money - and it's not hard to get. I have children in school every day with the white children. However are times there now?

But it was not only the prospect of employment, the desire to escape the drudgery of agricultural labor, or the need to escape racism that pulled the migrants northward. There was also the siren song of the bright lights and the big city. Vernon Jarrett, veteran columnist for the Chicago Tribune, and himself a migrant, recalled:

Radio had a tremendous impact in terms of making people dream of going North one day. You heard music coming from the Grand Terrace Café... Earl "Fatha" Hines, Duke Ellington...Cab Calloway...the young Count Basie. Chicago - this was a place where black people could talk back to white people - and could vote. We read the Chicago Defender and we would have great dreams and great fantasies about this place, this Mecca of human rights and civility. And of course, much of this was exaggeration, but it was the kind of exaggeration people needed to maintain hope in this country and their own lives.

Segregated residential patterns spawned flourishing institutions in black neighborhoods, including a thriving nightlife. On the musical front, rhythm and blues - born in the late 1940s of the fusion of blues, jazz, boogie-woogie, and gospel - was popularized by southern migrants such as Muddy Waters, who moved from Mississippi to Chicago in 1943; Bo Diddley, who left Mississippi in 1935 and also settled in Chicago; and Ray Charles, who migrated from Georgia to Seattle. R&B, an urban music, flourished on the South Side of Chicago, along Los Angeles' Central Avenue, and in Harlem, the neighborhoods that were home to the old and new migrants.