[Non-Sequitur]

No, but the power to admit, remove, or alter the make up of a state was reserved to the Congress in Article IV, Section 3. The unilateral act of secession as practiced by the southern states was illegal.

[4CJ]

No, but the power to admit, remove, or alter the make up of a state was reserved to the Congress in Article IV, Section 3.

The Article addressed the formation of NEW states only. It does not grant the federal government any power over what a state does with it's own territory. It does not grant a power to remove a state, nor prevent a state from seceding.