Justice Scalia, when ruling on the recent Hobby Lobby case, made it clear that corporations have constitutional rights, like people. Precedents have been set for all the amendments, except for the thirteenth.
Only the president can set this right, as Lincoln did in 1863.
Understandably, the function of a corporation is different than a person, so implementation will differ:
1. Individuals can still own corporations.
2. Companies may invest into each other up to 2/5 ownership
3. Companies may not share resources such as board members, staff or equipment.
4. Companies will be able to absorb the slave company, assuming all it's assets and liabilities
OR
5. Let it go with all of it's assets from the day of proclamation.
It was right the first time and it's right now.