San Juan Expedition (1780)

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

San Juan Expedition (1780)

During the American Revolutionary War, Britain tried to seize Granada and León on Lake Nicaragua by sailing up the San Juan River from Mosquitia. The operation was led by Captain John Polson (overall commander) with Captain Horatio Nelson as the naval leader, and about 3,000 men supported by ships.

What happened
- The expedition sailed from Jamaica in early 1780 and anchored off San Juan del Norte in March.
- On April 9, Nelson led a successful assault on a small Spanish battery. Fort San Juan was besieged from April 13.
- The British ran low on ammunition, rations, and, after heavy rains, diseases such as malaria and dysentery spread.
- Nelson fell ill and left the campaign in late April; the Spanish, commanded by Juan de Ayssa, surrendered Fort San Juan on or around April 28.
- British forces stayed at the fort for six months, while the Spanish strengthened the area around Lake Nicaragua.
- By November disease and supply problems compelled the British to withdraw. The fort was reoccupied by Spain after the British blew it up on leaving.

Outcome and aftermath
- The expedition ended in Spanish victory. It failed to reach Lake Nicaragua and to cut Spanish America in half.
- About 2,500 British soldiers and sailors died, mainly from disease; a number of ships were damaged or grounded.
- Don Juan de Ayssa, who helped defend the fort, was promoted and later became governor of Nicaragua.

Key people
- Spain: Matías de Gálvez (overall Spanish authority) and Juan de Ayssa (Fort San Juan commander)
- Britain: John Polson (overall commander) and Horatio Nelson (naval commander)
- Other forces: Included various colonial regiments and volunteers supporting the expedition

What was at stake
- The British hoped to gain access to the Pacific by capturing Granada and León, effectively splitting Spanish America. The expedition’s failure made it the costliest British disaster of the war.