Why is the name of the state Missouri not the name of the river Mississipi?

Question

Because the river only crosses the state and is a tributary from the main mississipi river.

Answer 1

Because the tributary is mainly located in the state of Missouri. So it is named after it. Just like saying the river of Mississippi, it also comes from the state of Mississippi.

Answer 2

The State of Mississippi (1817) was named after the river. The river, 'Mississippi' means 'large river' in the Chippewa
language. The river had been named as early as 1695 as it had been used on a map.
http://www.netstate.com/states/intro/ms_intro.htm

The State of Missouri became a state in 1820. By this time the name Mississippi was used as both the river and State. So the area took its name from its mighty river 'The Missouri", which then lead to where the Missouri got its name?

The Missouri River got its name from the the Indians as well. There was an Indian tribe living along the banks of the river. They had canoes and used the river. " The river was named for the Missouri Indians who lived along the banks. The name, Missouri, means "canoe haver.""
http://www.netstate.com/states/intro/mo_intro.htm

Answer 3

When Missouri was named, Mississippi was already taken.