The colonies were in crisis. They had to band together. That meant compromises. The genius of the founders wasn't that they were perfect men, but that they knew they weren't perfect men and you couldn't jump to an ideal world all at once.
Time and again they told us, we have begun this work, this grand experiment to achieve liberty and freedom for all, it will be up to future generations to continue to advance the principles set forth in the declaration. Yes, they meant everyone, just not tomorrow. Trying to do so would have ended the experiment before it got started.
So you cling to that pathetic, weak, half truth justification if you like... Just know it won't fly here.
I revere the founders not because they were perfect and righteous, but because they knew they, like all men are flawed. Constrained to some extent by the conditions of contemporary society. Same as now.
Each generation has advanced the cause of freedom and equality in keeping with the founding spirit of this country. The south took a step back. Clearly.
So, you are unable to find even the tiniest reference to the confederacy moving someday to freedom for all? That so.