Which river is known for forming the border between several Southern states?

The Mississippi River is well-known for forming the border between several Southern states. It stretches approximately 2,340 miles and flows from its source in Minnesota to the Gulf of Mexico. This river serves as a natural boundary for states such as Arkansas, Louisiana, Mississippi, and Tennessee, among others.

The Mississippi River has been historically significant for trade and transportation and has played a vital role in the development of the Southern United States. Its expansive watershed impacts agriculture, industry, and ecosystems across multiple states. The river's incredible length and strategic location also contribute to its recognition as a key geographical feature of the Southern region.

The Ohio River, although significant, primarily forms part of the border between states in the Midwest and the eastern United States. The Tennessee River is important but does not serve as a boundary between multiple states at the same level as the Mississippi. The Columbia River is primarily located in the Pacific Northwest and does not relate to the Southern states.