On April 13, 1862, the Union gunboats Ethan Allen and Beauregard arrived at Tampa. The Union commander, Acting Volunteer Lieutenant William B. Eaton sent Acting Master G.B. Stephenson under a flag of truce to demand the unconditional surrender of the town and Fort Brooke. Major Thomas declined and after allowing 24 hours to remove all women and children the Federals began bombarding the fort. The Union gunboats bombarded Tampa for two days with little to no effect before withdrawing.

On the morning of June 30, 1862, the USS Sagamore under the command of Captain A.J. Drake entered Tampa Bay. A launch started for shore with a lieutenant and 20 men under a flag of truce. They were met by Captain John Pearson and 18 men who rowed out from Tampa. Captain Drake responded to the request for unconditional surrender by stating he and his men did not know the meaning of the word surrender. After arriving back at Fort Brooke Captain Pearson moved part of his ammunition and all the women and children about a mile to the rear. The Sagamore opened fire at 6:00 PM firing 20 shots over an hour. The Confederates fired 22 shots from three 24-pounders. The Sagamore withdrew out of the range of the forts guns (about 2.5 miles) and resumed firing about 10:00 AM the next day for about 2 hours. Since they were out of range of the guns at Fort Brooke the Confederates did not return fire. The Sagamore fired two more shots around 2:00 PM and left. There were no casualties and little damage to either side. The affair is sometimes referred to as the “Battle” of Tampa.

Spanish Fort (two cannons in this park helped defend Fort Brooke)- In 1891 upon the completion of the Tampa Bay Hotel, Henry B. Plant recovered two Civil War cannon from across the Hillsborough River at the site of Old Fort Brooke. With his landscape architect Anton Fiehe, Mr. Plant placed the cannon over a limestone wall near here as a garden folly called The Spanish Fort. These 24-pounder cannon were part of a 3-gun battery in Fort Brooke during the Civil War. They and two 6-pounder rifled cannon successfully defended Tampa until May 5, 1864. On that date, federal troops, composed of elements of the 2nd U.S. Colored Regiment, the 2nd Florida Cavalry and the U.S. Navy, captured the town and fort by surprise. The 24 pounders were disabled by breaking off a trunnion and destroying their barbette carriages. The indentation on the barrel of one of the 24 pounders indicates that a 6 pounder was fired point blank at its barrel. The 6 pounders were then taken to Key West.

Text of the marker above- Originally part of a battery of three, mounted on Barbette Carriages and placed in the year 1861 near the northeast corner of the mouth of the Hillsborough River these 24 pound shot sized cannon were used to defend Tampa and Fort Brooke during the “War between the States”. On May 5, 1864 Federal Troops composed of elements of The 2nd U.S. Colored Regiment, 2nd Florida cavalry, U.S. Sailors and Florida Union (irregular troops) landing South and East of Tampa enveloped Tampa in a pincers movement and captured it by surprise. The 24 pounders were disabled and their mounts destroyed. Two smaller 6 pound shot size cannon were carried away. H.B. Plant while constructing the Tampa Bay Hotel is credited with saving these two cannon by bringing them to these grounds and including them in the “Childrens Fort” play area.