The only major civil war battle to happen in Florida occurred 50 miles out of Jacksonville in February of 1864.
Olustee Battlefield Historic State Park [5815 Battlefield Trail Road Olustee, FL 32087] commemorates this battle and does a great job teaching the story of the campaign leading up to it.
First head to the interpretation center to get your background, it is open from 9-5PM daily and includes a documentary, artifacts, and informational panels. Union troops wanted to disrupt Confederate food supply and had met little resistance in Florida until this point. They made their way from Jacksonville intending to head to the capital, Tallahassee. Confederates sent reinforcements and the two armies met at Olustee where 10,000 men would battle for the next five hours in a pine forest.
Union troops were forced to retreat back to Jacksonville after 200+ were killed, 1,100+ wounded, and 500+ went missing. It was the second bloodiest battle of the war for them with a loss of 34%. Confederates casualties were 946, about 19% of their men.
You can walk around the battlefield where the carnage took place on a one mile hiking trail, learning step by stop how it went down.
There are interesting quotes and facts on interpretive signs.
It is starkly tranquil today and you will likely see some wildlife. This is a habitat for the red-headed woodpecker, a near threatened species.
Good to know:
+The park is entirely free to visit
+On Presidents Day weekend a reenactment of the battle occurs
+The 1300 mile Florida National Scenic Trail runs through the park if you are looking to extend your day