Answer:
The ruling in Dred Scott v Sanford, issued in 1857 by the United States Supreme Court, was one of the Court's most contentious cases regarding the status of slaves and their citizenship in America.
Basically, the ruling confirmed the position held by the slave owners, which established that they were property and not human with American citizenship, with which they could not claim before the Court under any circumstances.
The ruling caused even more divisions in the already convulsed American society regarding the issue of slavery. In the North, whose society was largely abolitionist and where large numbers of states had already banned slavery, the ruling was seen as shame and disrespect for the human condition. In the South, by contrast, the ruling was seen as a triumph of property system and a confirmation of the supposed essential difference between the white man and the black man.