Final answer:
The lives of African Americans were affected when federal troops withdrew from the South due to increased hostility, racial tensions, and violence. Many African Americans also moved north to escape discrimination and find better job opportunities.
Step-by-step explanation:
When federal troops withdrew from the South, the lives of African Americans were significantly affected. They faced hostility and resistance from whites who did not tolerate their newfound freedom and equality. African Americans also experienced racial tensions and violence, as they came into closer contact with white people. Additionally, many African Americans from the South decided to move north to escape discrimination and seek job opportunities.