As pointed out to you earlier, no citizen was stripped of his rights. Secession in no way harmed any rights of persons living under the original Constitution.
The Confederate States wrote and adopted its Constitution by the consent of the citizens.
You seem a bit confused in your logic.
I believe that there is only one Constitution of the United States. I believe that there is only one United States of America.
And I believe that no person or group of persons can strip any other citizen of his rights under the United States Constitution or his status as a citizen of the United States. You and I apparently agree that no one was in fact stripped of his rights or his United States citizenship by the so-called "secessionists," but that is because the acts of the "secessionists" were then and are now a tragic nullity. However, at the time, the "secessionists" imagined that they were terminating the status of their neighbors as citizens of the United States of America. In fact, they actually imagined that they were creating a new nation of confederate states.
I think that you and I also agree that we are very fortunate that the "secessionists" failed in their efforts. Slavery is gone, and it is gone for good. Nearly all of of us are happy with that change and nearly all of the few people who aren't happy with that change lack the courage to admit it. So, their opinions don't matter, anyway.
In fact, there were huge regions of several Confederate states which refused to recognize declarations of secession and sent their young men to serve the Union Army.
Those regions included: Western Virginia, Eastern Tennessee, Western North Carolina, Northern Arkansas.
In addition, the Confederacy claimed sovereignty over Missouri and Kentucky, which never voted to secede, and sent the majority of their young men to the Union Army.
In the end, only South Carolina and Georgia, so far as we know, supplied no serious forces to the Union.
So obviously, not everybody in the South agreed that secession was such a great idea.