FLT-bird: "The fort [Barrancus] sat on sovereign Florida territory and was being illegally held by federal troops....and they are the ones who fired first."
If you will note the incident at Fort Barrancus (near Fort Pickens) happened the night of January 8, 1861, two days before Florida declared secession.
So their was nothing -- repeat nothing -- lawful about the secessionist civilians assault on Fort Barrancas and nothing illegal about the Union guards' response, period.
What was it they did to "assault" Fort Barrancas? My recollection is that they noticed activity, and simply went there to see what was going on, and then they got shot at by the Union soldiers there.
I hadn't heard that they tried to "assault" the place, so you can enlighten me by providing details of how they conducted this assault.