What is the longest north south river in the United states?

The Mississippi River is the longest north-south running river in the United States. Is is also the fourth longest river in the entire world.

The Mississippi is 2,320 miles long. Many other major rivers in the country are its tributaries, meaning they flow into it. Its drainage basin--that is to say, all the streams and rivers whose waters eventually end up in the Mississippi--covers the entire Midwest region of the United States.

The Mississippi begins in Minnesota, where it flows out of Lake Itasca, and ends in Louisiana when it empties into the Gulf of Mexico. It passes through eight other states. In fact, many state geographical boundaries are determined by this river. It was a major shipping route before airplanes and highways existed, and cities like New Orleans, St. Louis and Minneapolis were established near it to take advantage of this.