(A) southerners
(B) ** African Americans
(C) Native Americans
(D) i mmigrants
EXPLANATIONS BELOW
Concept note-1: -The First Great Migration (1910-1940) had Black southerners relocate to northern and midwestern cities including: New York, Chicago, Detroit, and Pittsburgh. When the war effort ramped up in 1917, more able bodied men were sent off to Europe to fight leaving their industrial jobs vacant.
Concept note-2: -Driven in part by economic concerns, and in part by frustration with the straitened social conditions of the South, in the 1870s African Americans began moving North and West in great numbers. In the 1890s, the number of African Americans moving to the Northeast and the Midwest was double that of the previous decade.