Fort New Richmond, British colonial fort on Mississippi River in Baton Rouge, United States.

Fort New Richmond was a British defensive fortification featuring earthen walls reinforced with palisades and armed with thirteen cannons. An 18-foot-wide (5.5 m) moat encircled the entire structure, serving as its outer defensive line.

Lieutenant Colonel Alexander Dickson built the fortification in 1779 to secure British military control over the Mississippi River during the American Revolution. Spanish forces under Bernardo de Galvez soon captured it and renamed it Fort San Carlos.

The fort represented a meeting point where British, Spanish, and American interests collided during military operations. The siege brought together Spanish regulars and American volunteers, reflecting the region's complex cultural makeup at that time.

The fort site lies on the east bank of the Mississippi River in downtown Baton Rouge, near the Pentagon Barracks and the old state capitol. No standing structure survives; look for historical plaques that mark the location and explain the siege positions. The area is accessible on foot and by car, with nearby public parking.

The siege ended British presence in the region and marked a turning point in control of the Mississippi River. This event is often overlooked despite showing how effectively Spanish forces reshaped power in North America.