Lincoln started the war, nitwit.
The Southern states fired on the US Flag
How despicable
It ought to be obvious, even to you, that no nation, however young, would tolerate a fort occupied by troops of a self-declared hostile power in the middle of its primary harbor! Major Anderson was repeatedly implored (very politely) to vacate the fort, peacefully. After he repeatedly refused (on Lincoln's orders) the South Carolina batteries shelled it, only enough to make clear they would take it by force if necessary. Anderson surrendered, after which he and his men were treated,
not as prisoners, but as honored guests, until passage North could be arranged for them. The few Union wounded were given the best of care, and there was only one fatality, which occurred when one of the forts own guns blew up, in firing a final salute. Some "aggression"! Compare that with Mr. Lincoln's stated intent (and later, failed attempt) to march an army across a non-belligerent sovereign state to attack the territory of another state. Do bear in mind that
at the time, most Americans considered themselves citizens of their state first, and Americans second.