There was no rebellion and were no rebels.
The Unites States was established as the international agent to administer the constitution for the several states in union.
The constitution is an international compact among the several nations of the union.
The constitution permits military action or intervention only in cases of insurrection or rebellion.
The Unites States is not a country or nation, and therefore secession from it is not an act of rebellion or insurrection.
Therefore the (so called) Civil War was an unprovoked illegal international war.
Then there is the time line:
1861 War declared to maintain the Union, specifically declaring that the war is not for the purposes of conquest.
1865 Southern states concede and the war ends. 13th amendment ratified.
1866 Peace declared. Southern states restored to full status under the union.
1867 Reconstruction Acts remove sovereign statehood from southern states declaring them territories of the US in rebellion and the US invades and militarily occupies them removing their lawful governments and replacing them with their own, an act of conquest.
1867-8 Occupation forces Southern states to ratify 14th amendment.
The problem is that the southern states were either states or territories. As rightful states, the occupation was unlawful, but if were merely territories, they were lawfully unable to ratify the 14th amendment.
Conclusion: Criminal and treasonous behavior by the president and congress at every turn.
~ Engage in the war of attrition: http://pacalliance.us/redamendment/