The two longest rivers in the United States are the Mississippi River and the Missouri River. The Mississippi River runs through ten U.S. states. It starts in Minnesota near the border we share with Canada. It ends in Louisiana. The Missouri River starts in Montana. It joins the Mississippi River in the state of Missouri. The rivers have always been important to people living in the United States. American Indians used the rivers for trade, food and water. People still use the rivers to transport products. They are an important source of water. The two longest rivers in the United States are the Mississippi River and the Missouri River.