What is the best source for this in your view?
The raw data is plentiful -- look at any standardized test scores (e.g. SAT) by race. For a full-blown argument in favor see e.g. this (I can't check the link at the moment, it might be that you need to go to the Wayback Machine to access it). For a more, um, mainstream discussion see Charles Murray's The Bell Curve. Wikipedia has more links you could pursue.
Is it your view that past slavery in America still has a large impact on African Americans in the present day U.S.?
My view is that history is important and that outcomes are path-dependent. Slavery and segregation are crucial parts of the history of American blacks.
open to learning
Your social circles might have a strong reaction to you coming to anything other than the approved conclusions...
If it's worth saying, but not worth its own post, then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should start on Monday, and end on Sunday.
4. Unflag the two options "Notify me of new top level comments on this article" and "