For quite a while, I had thought that the verdict ruled that Scott couldn't sue for citizenship because slaves couldn't sue in court because slaves do not have the legal privileges of US citizens. Upon further study, I realized the wording was not slaves, it was people of African descent. The ruling also says that states may give people of said descent the privileges that white people held, but they could not be made citizens of the US because it was not within the power of states to do so. What did this mean for "free" Africans in the US? Did this essentially mean that a state could call them free, but that they still wouldn't be US citizens?
In short, Scott v. Standford (1857) allowed for the federal government to discriminate on the basis on race when it comes to citizenship. This action by the Taney court (a 7-2 decision) had the effect all of "the negro African race... whose ancestors who imported... and sold as slaves." were not U.S. citizens. This included both free and enslaved peoples.
This situation meant that while states could confer citizenship, they would not be citizens of the United States, nor enjoy the privileges that come with citizenship. The court decision was overturned in 1868 by the ratification of 14A, which I have outlined the first section of below:
Amendment XIV
Section 1.
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside. No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any state deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.