États-Unis dans la Première Guerre mondiale
In early 1919, the sociopolitical atmosphere of Chicago around and near its rapidly-growing black community was one of ethnic tension caused by racism and competition among new groups, an economic slump, and the social changes engendered by the involvement of the United States in World War I. With the Great Migration, thousands of African Americans from the American South had settled next to neighborhoods of European immigrants on Chicago's South Side near jobs in the stockyards, meatpacking plants, and industry. Meanwhile, the Irish had been established earlier, and they fiercely defended their territory and political power against all newcomers. Post-World War I racism and tensions caused inter-community frictions, especially in the competitive labor and housing markets. Overcrowding and the increased African American resistance against racism, especially by war veterans, contributed to the visible racial frictions. A combination of ethnic gangs and police neglect further exacerbated racial tensions.