The area that Fort Clinch State Park now sits on has always been important land strategically. It is the entrance to the Cumberland Sound and the St Mary's River. That is why in 1736, way before the United State declared independence, the first fortifications were built there. It is no way as extensive as the fort that stands today, that would come almost a century later after the war of 1812. The war of 1812 was brutal for the barely 30 year old country. It installed fear about the country's security, especially since Washington DC had been essentially burned to the ground by the British. Soon the country planned "Third System Fortifications" or a number of forts to be built along the coastline of the United States to protect the new country's borders.
Fort Clinch was a part of this plan and began construction in 1847. It was envisioned as a towering force to be built by the US Army Corps and local civilians. Unfortunately another war was brewing, this time from inside the country itself. The fort was about two thirds done when the Civil War broke out. Confederates soon took control of the fort, despite it being unfinished, and used it to fortify southern shores. The confederates eventually evacuated and it became Union controlled in 1862. Construction began once again, but was not completed until the end of the war in 1869 and was left empty. It was used again briefly in 1898 in the Spanish-American War and updated slightly, but in 1926 it was sold by the army to private companies. It officially became a Florida State Park in 1936.
Now this site serves less of a strategic purpose and more of a place for Floridians to learn both about history and relax in the sun. Guests can not only tour the old fort, but participate in other activities including Bicycling, Bird Watching, Camping, Paddling, Fishing, Geocaching, Hiking, Mountain Biking, Picnicking, Shelling, Surfing, Swimming, and Wild-Life Viewing.