Answer: The Great Migration. The great migration was an event where millions of African Americans migrated to the north for better living conditions, working conditions jobs, etc.
Answer 2: African Americans were heavily assaulted in the south due to the southern population being extremely racist. People would go out of their way to make fun of a black man, spit on them, and or assault them. (Example: Emmit Til) The Jim Crow Laws were segregation laws which promoted racial activity in the south.
(Hope one of these helped)