The Mississippi River is the longest river in the U.S.A.

Mississippi : a major north American river and the chief river of the United States; rises in northern Minnesota and flows southward into the Gulf of Mexico.

The Mississippi River is a tributary of the Ottawa River in eastern Ontario in Canada.

This is the website we got these facts from: https://sites.google.com/site/mississippiriverfactsnvj/

http://www.socialstudiesforkids.com/articles/geography/mississippiriver.htm 

http://earthobservatory.nasa.gov/IOTD/view.php?id=78903

Here are some more facts:

The Mississippi, especially in its lower sections, can overflow its banks with disastrous results for the people living nearby.

Many different kinds of wildlife make their homes in the Mississippi River including 241 species of fish, 37 spices of of mussel, 45 amphibians, 50 mammals, and full of 40% of the entire country’s migratory birds.

Th length of the Mississippi River is 3,870 miles.

In the spring of 2011, The Mississippi River swelled to historic levels, rising out its banks, rolling across a wide flood plain, and eating at flood barrels.

The Mississippi River is a major North American transit route, carrying goods to and from ports in New Orleans and Baton Rogue.