Did Spanish and French both hold claim to the Mississippi River?

Yes, both Spain and France held claims to the Mississippi River at different times. France initially explored and claimed the river in the 17th century, establishing New France along its banks. Following the French and Indian War in 1763, Spain acquired control of the territory west of the river, including portions of the Mississippi River basin. However, France regained control briefly in 1800 before selling the Louisiana Territory, including the river, to the United States in 1803.