[Pontiac]

The very occupation of the fort by the army of a foreign power is a provocation.

But it was their fort. How can that be a provocation?

Where territory or other property within the states boarders had been ceded to the Federal government by the state for its use it could be assumed that that territory or other property would revert to the state upon that state leaving the union.

This only makes sense because to assume otherwise would be to have an outpost potentially hostile foreign entity within your boarders.

[DoodleDawg]

Where territory or other property within the states boarders had been ceded to the Federal government by the state for its use it could be assumed that that territory or other property would revert to the state upon that state leaving the union.

Based on what rule of law or what clause of the Constitution?

This only makes sense because to assume otherwise would be to have an outpost potentially hostile foreign entity within your boarders.

One of the many reasons why a negotiated separation would be preferable to unilateral secession. It would give both sides a chance to deal with any issues of potential disagreement before parting. But a peaceful separation was not what the South wanted apparently.