African American migration to the urban North during the First World War was due primarily to

Driven from their homes by unsatisfactory economic opportunities and harsh segregationist laws, many Black Americans headed north, where they took advantage of the need for industrial workers that arose during the First World War.

Explanation:

the answer is migration

nuclear fission produces the atomic bomb, a weapon of mass destruction that uses power released by the splitting of atomic nuclei the fighting in iwo jima and okinawa affected the allies' pacific strategy because truman decided to drop the atomic bomb on mainland japan.