The Treaty of San Lorenzo, also known as Pinckney’s Treaty, was an agreement between the United States and Spain that settled a boundary dispute and granted navigation rights on the Mississippi to Americans. Spain had lost possession of modern-day Florida to England during the French and Indian War. The Treaty of Paris in 1783 returned this area to Spanish control, however, Spain claimed the boundary of West Florida was 85 miles further north than America insisted upon. In retaliation, the Spanish closed the port of New Orleans to all American goods, which hurt western commerce. To resolve this dispute, President George Washington sent South Carolinian Thomas Pinckney to Spain to negotiate a settlement.

The Pinckney Treaty ended a border dispute with Spain, opened the Mississippi and New Orleans to commerce and helped bring our nation closer together.