Did the anti federalist oppose slavery?

No, Antifederalists were those who favored a less centralized national government.

SECOND ANSWER: I am not sure of the "position of the Anti-Federalists" on slavery (as if they all held the same view on it; highly unlikely), but whoever posted the first answer is a f*cking idiot. Since when does supporting a less centralized federal government constitute the support of slavery? If you are going to answer a question, you should stick to answering the question; not trying to classify two different positions as mutually inclusive.