Walter Francis Willcox, 1922 Encyclopædia Britannica (1922)
“ The sharp check in the growth of negro population between 1910 and 1920 was due primarily to the flood of migration from the agricultural districts of the South largely to the cities and industrial districts of the North, but partly also to the cities of the South, and the exposure of negroes in their new homes to conditions tending to raise the death-rate or reduce the birth-rate, or both. ”
