The Ashbrook Center for Public Affairs in Ashland, Ohio will probably be surprised to learn that they are neoconfederates. As for "clipping Douglass off mid sentence" I stopped at a paragraph, as did you. The entire speech is available at the link I posted.
You stopped at a paragraph that left the impression that Douglass thought Lincoln was uninterested in blacks. The reality is the Douglass said that Lincoln did more for blacks than was thought possible.
Selective quoting (and outright lies) are the only thing that keeps the neo-confederate mythology alive.