Why isn't the Mississippi river called the Missouri?

Answer 1

The Mississippi River and the Missouri River are two separate rivers.

Answer 2

The Mississippi River is named after the Native American Ojibwe word "misi-ziibi," meaning "Great River." The Missouri River is the longest tributary of the Mississippi River, and it was named by the Native American Algonquian people, meaning "people with wooden canoes." The Mississippi River is named according to its significance and size in the region, while the Missouri River is named after the people who lived along its banks.