Answer:
The Black Codes, sometimes called Black Laws, were laws governing the conduct of African Americans (free blacks). The best known of them were passed in 1865 and 1866 by Southern states, after the American Civil War, in order to restrict African Americans' freedom, and to compel them to work for low wages.
It helps you understand by showing you that even though African Americans were considered free, the laws were made in a way that they were still under the control of the people who once enslaved them.