The Battle of Bloody Marsh took place on July 18, 1742 (new style). The battle involved control of the road between the British forts of Frederica and St. Simons, both on St. Simons Island off the coast of Georgia. The Province of Georgia later claimed the island, now in the U.S. state of Georgia. The battle took place on the same island and same day as the Battle of Gully Hole Creek.
This was one of the conflicts during the War of Jenkins' Ear. The catalyst was Spanish officer Julio León Fandiño's cutting off one of Robert Jenkins' ears. Jenkins, accused of piracy, was a British sea captain whose brig Rebecca was boarded by troops of the Spanish Coast guard Ia Isabela. They found he was smuggling. Jenkins reported the Spanish captain told him, "Go, and tell your King, that I will do the same, if he dares to do the same."
In retaliation for the boarding and assault on its officer (and related to tensions having built between the two nations), on October 30, 1739, Great Britain declared war on Spain. Spain and Great Britain had been disputing the border between Georgia and La Florida. James Oglethorpe led the colonization of Georgia for Great Britain, choosing Savannah as the principal port for the new colony.
With the heightened threat of Spanish invasion, Oglethorpe sought to increase southern defenses. Accompanied by rangers and two Native American guides, Oglethorpe picked St. Simons Island as the site for a new town and fort. In 1734, Oglethorpe convinced the Parliament and the colonial trustees to pay for a new military garrison. He recruited a company of British settlers to migrate with their families to live at Darien, at the mouth of the Altamaha River. The trustees also selected a large new group of colonists for St. Simon's Island. The ships bearing the settlers and supplies arrived at Tybee Island early in 1736. From there, some went to the mainland while others set off south in periaguas to St. Simon's Island to found the new town of Frederica. Frederica and its fort were built on the elbow of the Frederica River to control approaches from both directions.
In 1737, Oglethorpe returned to England to acquire more funding and permission to raise a regiment of soldiers, and was successful in convincing Parliament of both. He was appointed commander-in- chief of all British forces (limited as they were) in the colonies of South Carolina and Georgia.
They found the road between Fort St. Simons and Fort Frederica, but first assumed the narrow track was just a farm road. After realizing the mistake, Montiano sent about 300 men to reconnoiter the road. On July 18, Spanish troops and a group of British soldiers, under command of Nobel Jones, skirmished with each other. Defeated by the British, the Spanish soldiers told their opponents that the larger Spanish army was advancing along the road from Fort St. Simons to Frederica. Oglethorpe positioned some men as rear guards.
Oglethorpe left to get more recruits. In another skirmish between the forces, the heavily outnumbered British began to retreat. When they reached a bend in the road, Lieutenants Southerland and Macoy decided to stop, and their regiments and allied Indians hid in the dense forests. They watched as the Spanish broke rank, stacked arms and, taking out their kettles, prepared to cook dinner, as if the British had retreated for good. Instead, the forces burst from the forest and attacked the Spanish off-guard, killing about 50 (estimates vary). British forces routed the Spanish, and Oglethorpe, although not leading his forces, was credited with the victory.
Oglethorpe continued to press the Spanish, trying to dislodge them from the island. A few days later, approaching a Spanish settlement on the south side, he learned of a French man who had deserted the British and gone to the Spanish. Worried that the deserter might report the small number of British men, Oglethorpe spread out his drummers, to expand the sound of military drums as if they were a larger force. He wrote to the deserter, addressing him as if a spy for the British, saying that the man just needed to continue his stories until Britain could send more men. The prisoner who was carrying the letter took it to the Spanish officers, as Oglethorpe had hoped. Lastly, Oglethorpe arranged for some British ships to sail near, to suggest more forces were arriving. The Spanish left the island on 25 July, finishing their last invasion of colonial Georgia.