What adverse effect emerged from African Americans migrating north in search of jobs during world war 1

B) This is a very complicated question for a multiple choice answer. A friend of mine is writing her thesis on this exact topic. Race riots were common in cities like Chicago, Cincinnati, Detroit, etc. It actually forced wages down across the board for laborers and women were not yet in the work force in large numbers (not until WW2). Population was generally unchanged and illegal immigrants tended to go towards large cities.