The United States Government didn't have the stature to say that.
The seceding States were the People. When the People say something, their servants do not contradict them.
Secession and ratification were alike sovereign acts of the People subject to review only by God Himself. Or do you think that your government is empowered to stand over you with iron rods and tell you what your rights are and are not, and what your duties are, and what you are going to do right now?
We're just about there in practice .... are you going to go the last few yards and drink the Kool-Aid, and tell us, with all your heart and your dying breath, that you deeply and truly bellyfeel Big Brother? Signify to us.
Please see my last post. No, those people were clearly not the People, in and of themselves. If there were an Constitutional Convention, held by the process described in the US Constitution, that would have been "We the People." Good reason based upon faulty premeses is bad reason.