http://www.newsweek.com/mississippi-river-facts-how-long-1785020 > The enormous Mississippi River, the 13th largest river in the world in terms of flow, occupies a central place in U.S. geography, economy and culture. > The river is a huge part of the country's agriculture system, with 92 percent of the nation's agricultural exports being produced in the Mississippi basin, which equates to 78 percent of the world's soybeans and grain exports.