The correct answer to this open question is the following.
Although the question does not provide the article, we can say that the idea that completes the summary is that although slavery was prohibited after the Civil War, during the Reconstruction time the southern states had a different opinion and did not accept that African Americans integrated into the southern society and intermingle with the white people of the South. Indeed, things got worse because many southern states created legislation like the Jim Crow laws and the Black Codes, that segregated African Americans.