Name one of the two longest rivers in the United States.

The USCIS Civics Question 88 asks to name one of the two longest rivers in the United States. The accepted answers are the MISSOURI RIVER and the MISSISSIPPI RIVER. The Missouri River (approximately 2,341 miles) is technically the longest river in the US by most measurements, though historically it is the Mississippi that receives greater recognition as America's great river. The Mississippi River (approximately 2,340 miles) drains the third-largest river basin in the world, covering about 40% of the contiguous United States. Together, the Missouri-Mississippi river system is one of the largest in the world. The Mississippi River has been central to American history and culture: Native Americans used it extensively; European explorers including Hernando de Soto (1541) traveled it; the river was crucial for transportation and commerce in the 18th and 19th centuries; Mark Twain immortalized it in 'The Adventures of Huckleberry Finn' and 'Life on the Mississippi.' The river system flows south from Minnesota and drains into the Gulf of Mexico near New Orleans, Louisiana. For the USCIS test, either 'Missouri River' or 'Mississippi River' is an acceptable answer.