Answer:
The Mississippi River formed the eastern boundary and the Rocky Mountains formed the western boundary of the Louisiana Territory.
Step-by-step explanation:
The Mississippi River was chosen as the eastern boundary of the Louisiana Territory because it was already a well-established boundary between the United States and the Spanish Empire. The Rocky Mountains were chosen as the western boundary because they marked a natural barrier that would be difficult for Europeans to cross and settle beyond, making it easier for the United States to control and develop the territory.