bguy
Donor
As pointed out, it would be meaningless. Anyone could bring a slave into a Confederate 'free' state and keep them there working indefinitely. You could even sell your slave while he or she was in the Confederate free state.
What would keep a Confederate 'free' state that really, didn't want people bringing slaves into their state from simply seizing any slaves in its borders pursuant to the state's impressment power? Seven Confederate states passed impressment legislation in 1862/1863 and the Confederate national government passed such legislation in 1863, so impressment appears to have been permissible under the Confederate Constitution, and that would give any Confederate 'free' states a powerful tool to discourage slave owners from bringing slaves into any free states. After all a Mississippi slave owner isn't likely to risk bringing his slaves with him when he visits 'free' Tennessee if he knows the Tennessee state government will promptly impress his slaves for the next five years.
And anyway, its not as though the Confederate Constitution was all that difficult to amend. The Confederate Congress didn't even have a vote in the amendment process and it only took 2/3 of the states to approve a constitutional amendment (as opposed to the U.S. where an amendment typically requires a 2/3 vote for both houses of Congress and then ratification by 3/4 of the states), so its not as though any constitutional prohibition would be that difficult to get around if there ever starts to be genuine popular support for getting rid of slavery (or at least making it easier for individual states to prohibit slavery within their borders.)