What are the two longest rivers in the United States?

The Mississippi and Missouri Rivers are indeed the two longest rivers in the United States. The Mississippi River, which flows approximately 2,340 miles from its source at Lake Itasca in Minnesota to the Gulf of Mexico, plays a crucial role in American history, economy, and ecology. The Missouri River, at about 2,341 miles, is slightly longer, beginning in the Rockies of Montana and also draining into the Mississippi River. Together, these rivers form a significant river system that has been vital for transportation, agriculture, and trade throughout U.S. history.

The other options do not feature rivers that match the lengths of the Mississippi and Missouri Rivers. While the Ohio and Tennessee Rivers are important waterways, they are significantly shorter. Similarly, the Colorado River, although famous for its canyons and water resource importance, does not compare in length to the Mississippi and Missouri Rivers. Lastly, the Rio Grande is notable for its role as a border river between the United States and Mexico, but it is also not one of the longest rivers in the country compared to the top two.