As the previous educator mentioned, former slave owners tried to continue to force labor out of black people. There were two ways in which this was accomplished in the late-nineteenth and early-twentieth centuries: convict-leasing and sharecropping. The sharecropping system was one in which there may have been a contract to work. Unlike indentured servitude, in which one promised to work for a certain number of years in exchange for money or property, sharecroppers could live on a planter's property for life. They labored in exchange for a share of the harvest and a share of the earnings. It was not unusual for planters to cheat those who worked for him.
Another way in which whites limited the freedom of blacks was through disenfranchisement or, in other words, finding ways to prevent black people from voting. During Reconstruction, numerous black men from Southern states became representatives and senators. This new political power presented a profound threat to white supremacy in the South. Disenfranchisement prevented the development of black political power in the South, which has only recently changed with the elections of black, conservative politicians, such as former Representative J.C. Watts of Oklahoma and Senator Tim Scott of South Carolina.
Poll taxes and, later, citizenship tests became methods of preventing black men from exercising the right to vote—a right guaranteed in the Fifteenth Amendment. When this did not work, racists resorted to terrorism. The Ku Klux Klan was formed during the Reconstruction years and was resurrected in the 1920s. The KKK kidnapped and hung blacks who disrupted white power. They also torched people's homes in the middle of the night. Cross-burnings in front of one's home served as a warning.
I would argue that many of these methods were, unfortunately, successful. When one measures the quality of life and household income of black families versus those of white families in the South, the differences are stark. This is due to decades of political and economic oppression, which included the destruction of viable black communities (e.g., Greenwood in Tulsa and Rosewood, Florida).