Samuel Granados López

The historic limits of New Spain in present-day United States

This map shows how the boundaries of the Viceroyalty of New Spain (circa 1795) overlap with the current map of U.S. counties, highlighting the areas that were under Spanish administration.

A red line north of Florida shows the border as agreed by the Treaty of San Lorenzo, also known as Pinckney’s Treaty, on October 27, 1795. This treaty was signed by Manuel de Godoy in the name of Spanish King Carlos IV and Thomas Pinckney, representing the U.S. and later ratified by George Washington. It resolved territorial disputes between the United States and Spain in the present-day states of Alabama and Mississippi, setting the 31st parallel as the Florida border and granted American ships the right to free navigation of the Mississippi River as well as duty-free transport through the port of New Orleans, then under Spanish control.

A blue line showing the path of the Mississippi river determines the eastern border of the province of La Luisiana, which encompassed the western basin of the Mississippi River south of the 49th parallel plus New Orleans. The area had originally been claimed and controlled by France, which had named it La Louisiane in honor of King Louis XIV in 1682. Spain acquired it through the Treaty of Paris in 1763 as compensation for losing Florida, which Spain regained in 1783.

A green line in the west marks the continental divide in the west, the limit claimed by Spain for the Territory of Nutca or San Lorenzo de Nutca, which was part of the Viceroyalty of New Spain from 1789 to 1795 including the islands of Nutca, Quadra and Vancouver, Flores and others in the Strait of Georgia, as well as the entirety of the current Lower Mainland, in British Columbia and the southern half of this Canadian province; as well as the states of Washington, Oregon, Idaho and parts of Montana and Wyoming in the United States. It was governed from Mexico City from 1789 to 1795, when it formed part of the Viceroyalty of New Spain. Spanish claims in the Pacific Northwest extended up to the 61st parallel during Spain’s expeditions around 1790. These expeditions confirmed Spanish sovereignty in areas like present-day Cordova, Orca Inlet, Gravina Point, and Valdez.

An orange line marks the later Adams–Onís Treaty (1819-1821) agreed between Luis de Onís representing Spanish King Fernando VII and U.S. Secretary of State John Quincy Adams. With this treaty the border was set beyond the Sabina and Arkansas rivers to the 42nd parallel north. Consequently, Spain renounced its possessions beyond that latitude, including the Oregon Territory, which until that date was an area disputed also by the British. With this treaty Spain also gave up the Floridas, Louisiana and navigation on the Mississippi River. The Spanish Crown remained the sole sovereign of Texas, a territory that the United States claimed as part of Louisiana, purchased from the French in 1803.