What Was Known as the Great Migration

What was known as the Great Migration?

A) the mass movement of African Americans from the South to the North in pursuit of better living conditions and jobs
B) the influx of refugees from Europe following the Great War, resulting in a scramble to find them enough food and housing
C) the return of many African Americans from the South to Africa following the Emancipation Proclamation
D) the surge in the number of white settlers moving West due to the promise of gold and voting rights for women
E) the relocation of many African Americans from the inter-cities to the country in search of sharecropping jobs