Located near the mouth of the St. Johns River, this site was an important military position during the Civil War, allowing access to the inland areas of Florida's east coast. There was never an actual fort on Yellow Bluff, but an encampment that was fortified and equipped with large guns for protection. Constructed in 1862, the site was occupied by both Confederate and Union troops during the Civil War and-at its peak-housed over 250 soldiers. The site has a T-shaped earthworks and covers about 1.3 acres. Located on Yellow Bluff peninsula on the north side of the St. Johns River (on New Berlin Road).

Yellow Bluff Fort was constructed in 1862 by the Confederate army to ?relieve the valley of the Saint John?s from the marauding incursions of the enemy (Union army)?. Brigadier General Joseph Finegan, the Confederate commander in East Florida, issued the orders to build the fort on the Saint John?s River. This was an important position on a river that offered a direct route to Jacksonville for the shipment of goods, as well as easy access for attacks by invaders. There was never an actual fort on Yellow Bluff, but an encampment that was fortified and equipped with large guns for protection.

After a Confederate victory in the Battle of Olustee, Federal forces returned to Jacksonville. In anticipation of a Confederate attack, Federal forces fortified the St. John?s River including Yellow Bluff, which was captured on October 3, 1862. At 11 a.m. on February 28th, 1864, Companies B and J of the 55th Massachusetts Regiment (colored) under the command of Lieutenant Colonel Charles B. Fox boarded the steamer ?Charles Houghton? for Yellow Bluff. The group of 163 enlisted men and 8 officers arrived at Yellow Bluff at 12:30 p.m. On March 1, Company K of the 55th Massachusetts (colored) under Captain Charles C. Loule arrived, adding 85 more enlisted men and one officer.

The next day a corporal and 4 enlisted men from the New York Volunteers arrived with orders to build a signal station, which was begun on March 3. Second Lieutenants Thomas E. Webber and Charles Weihl and nine men of the Signal Corps came to Yellow Bluff on March 15 to man the tower. By March 24, the post was labeled ?effective?, and all ships operating on the St. John?s River were ordered to anchor only at Yellow Bluff. By the end of March, Yellow Bluff was home to 346 enlisted men and 10 officers. The 8th Regiment of United States Colored Troops (USCT) took over duties at Yellow Bluff, arriving on April 17. By the first of May, eight companies (37 officers and 141 men) of the 8th USCT were present at Yellow Bluff. Many different companies, including the 3rd and 34th USCT, were stationed at Yellow Bluff until the end of the Civil War.