How does the language of the 14th Ammendment bestow citizenship upon the former slaves? It nowhere says "all those who used to be slaves are hereby granted citizenship." All it says is the following:
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 interpretation of those words that does not obviously bestow citizenship on the former slaves can possibly be valid. The interpretation that requires that only the children of citizens become automatic citizens by birth fails to do that, and is therefore provably incorrect.
The Fourteenth Amendment was originally ratified to protect the freedman from the abrogation of his rights by the Southern states. Looking to protect the African American, the amendment made him a citizen and forced the federal government to be responsible for him. The Fourteenth Amendment prohibited the States from denying or abridging the fundamental rights of every citizen and required them to grant all persons equal protection and due process."
After the Civil War former slaves were made citizens, so their kids would fall under the automatic citizenship clause.