South Carolina opened fire on Ft Sumter - or are you ignorant to the fact that the United States is made of sovereign states?
As I am sure, that you are clueless to the fact that the Ft Sumpter standoff was in fact a standoff because Lincoln lied to the South Carolina delegation that came to Washington, telling them that he would not resupply the fort.
When the supply ship arrived, South Carolina knew that Lincoln had lied to them.
The ship was there to evacuate the forts garrison.
I would be very interested to see a link to an authoritative source that confirms this claim that Lincoln told anyone (much less a “delegation” from South Carolina) that he would not resupply the fort.