The answer is domestic system
The Financial Crisis and Great Recession
Not to much if you take into account the factors of underdeveloped economy at the time, trade was a means of living, and the classes standings played a role in where you stood in a economy
Because they got tired of oppressing south.
South was also tired of military rule. As the South got more and more upset about the military rule, North came under more pressure to end it.
The only reason for military rule was protecting the black rights. Most of the North didn't care abot black rights.
This was the reason why reconstruction ended.
The answer is Both A and B.