1) Voting Restrictions- by using poll taxes, literacy tests, etc. white Southerners tried to prevent African-Americans from voting and participating in the political process.
2) Special laws such as the Black Codes and the Jim Crow Laws- the segregation of public facilities by keeping black and white people separate from the 1870s through the 1960s.
3) The rise of the Ku Klux Klan (KKK) and the intimidation of freed black people by members their members preserved a 'Southern culture' dominated by wealthy white people.