According to the terms of the 1783 Treaty of Paris that ended the American War of Independence and included Spain as a signatory, British settlements on the "Spanish Continent" were to be evacuated, using language that was similar to that in the 1763 Treaty of Paris that ended the Seven Years' War.
[1] After both sides increased military activities in the area of the Black River Settlement, where most of the British settlers lived, it was decided to engage in further negotiations to resolve the issue.
In the agreement signed 14 July 1786, Britain agreed to evacuate all British settlements from the "Country of the Mosquitos".
In exchange, Spain agreed to expand the territory available to British loggers on the Yucatan Peninsula, and allowed them to cut mahogany and other hardwoods that were increasing in value.
Control of Black River was formally turned over to the Spanish on 29 August 1787, by the grandson of its founder, William Pitt.