2 Reasons they had to leave was 1. They were sold to cocasion/white owners and they had to leave, and 2. The cocasion slave owners felt that the a african americans didn't belong so they took them and beat them and stuff like that. (that is cruel man) Happy to Help! :D
Between the period of 1910 to 1930, there was a migration movement called the Great Migration that made millions of African Americans move from the Southern States to the North and West, it is estimated that 6 million African Americans relocated during this period.
The main reason for the Great Migration was that the Southern States limited African Americans rights which made living very difficult, African Americans could not buy property, marry, vote and other things.
Because the title does not show a lot about the article except what it's about. You may be able to tell by the author because the author may have written reliable or unreliable information before.