|Origin||Escambia County, AL|
|Length||65 miles (105 km)|
|Mouth elevation||sea level|
Perdido River is a 65.4-mile-long (105.3 km) river in the U.S. states of Alabama and Florida; the Perdido, a designated Outstanding Florida Waters river, forms part of the boundary between the two states along nearly its entire length and drains into the Gulf of Mexico. During the early 19th century it played a central role in a series of rotating boundary changes and disputes among France, Spain, Great Britain, and the United States.
It rises in southwestern Alabama in Escambia County approximately 8 miles (13 km) northwest of Atmore. It flows south approximately 5 miles (8 km) to latitude 31°N, south of which it forms the remainder of the Alabama/Florida border. It flows generally east-southeast in a winding course and enters the north end of Perdido Bay on the Gulf of Mexico, approximately 10 miles (16 km) west of Pensacola.
The word "perdido" is Spanish for "lost".
From 1682 to 1763, the Perdido formed the boundary between the French colony of Louisiana and the Spanish colony of Florida. Following the British victory over the French in the French and Indian War, Great Britain received the French colonial territory between the Mississippi River and the Perdido River, as well as the Spanish colony of Florida, while Spain received the French territory west of the Mississippi. The British divided the new territory into West Florida and East Florida at the Apalachicola River (whose main tributary, the Chattahoochee River, forms a large portion of the present boundary between Alabama and Georgia, and a small part of the Florida/Georgia boundary). In 1783, as part of the Treaty of Paris, Britain returned all of Florida to Spain, which at the time controlled all of the coast of the Gulf of Mexico.
In 1800, as part of the Treaty of San Ildefonso, Spain returned the Louisiana colony to France, retaining control of the territory east of the Mississippi, as Florida. In 1804 France subsequently sold Louisiana to the U.S. in the Louisiana Purchase. A boundary dispute erupted between the U.S. and Spain, with the U.S. claiming the land west of the Perdido as part of the original French territory of Louisiana, whereas the Spanish claimed that only the portion of Louisiana west of the Mississippi had been returned to France. The Gulf Coast south of 31 degrees latitude, between the Mississippi and Perdido rivers, remained disputed between the two nations. In 1810 West Florida successfully declared its independence from a weakened Spain. Ninety days later, U.S. military forces entered its capital and took control over the short-lived nation. The dispute was finally resolved in 1819 in the Adams-Onís Treaty, in which Spain ceded all of Florida to the United States. The Perdido River became the boundary between the state of Alabama and the Florida Territory in 1822.
- U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National Map, accessed April 15, 2011
- U.S. Geological Survey Geographic Names Information System: Perdido River
- Perdido River Watershed - Florida DEP