Technically, they were in revolt at the time of secession. The question of what to do at that point was not clear, especially given that Lincoln had not been inaugurated at the time, and Buchanan was not willing to act.
The nice gentlement of South Carolina kindly broke the logjam when they fired on Ft. Sumter.
Technically, they were states of the CSA. I forgot to include you in my response to rockrr @ post 281.