It would not matter legally what Congress said in 1868, if Court did not say it did. But there was also debate of sorts in 1898. Between the majority of the Court and the minority of the Court. Try reading that. And remember, debates are not law. The law is what was passed and subsequently interpreted by courts. See Wong Kim Ark!
Laws are upheld by the courts they don't interpret them. They can read the intent from the debates.
And I correct myself. My great links are to the Congressional Record pages of the debates.
As a matter of fact...here ya go...
14th Amendment to the U.S. Constitution: Primary Documents in American History
Yeah, it's called the dissent. As you say, DUH!