Short answers, pulled from the story.
The Mississippi River runs 2,340 miles from its traditional source at Lake Itasca in northern Minnesota to the Gulf of Mexico. Measured from its longest stream source, Brower's Spring in Montana at the head of the Missouri River, it stretches 3,710 miles, making it the fourth-longest river in the world.
The name Mississippi comes from Misi-ziibi, the Anishinaabe name used by the Ojibwe meaning Great River, which the French rendered as Messipi. Earlier European explorers gave it other names, including River of the Holy Spirit by Hernando de Soto in 1541 and Colbert River by La Salle in 1682.
The Atchafalaya River offers a much steeper, more direct path to the Gulf of Mexico, so the Mississippi naturally tends to switch into it through a process called avulsion. To prevent this, Congress authorized the Old River Control Structure, completed in 1963, which diverts 30 percent of the flow while keeping the main channel past Baton Rouge and New Orleans.
Control of the Mississippi River was a strategic objective in the American Civil War and formed part of the Union's Anaconda Plan. The Siege of Vicksburg ended on the 4th of July 1863, and combined with the fall of Port Hudson it gave the Union the entire lower river and proved pivotal to its victory.
The Mississippi River and its tributaries drain all or parts of 32 U.S. states and two Canadian provinces, covering nearly 40 percent of the continental United States. The river itself borders or passes through Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana.
Water skiing was invented on Lake Pepin, a wide stretch of the Mississippi River between Minnesota and Wisconsin. Ralph Samuelson of Lake City, Minnesota, created and refined the technique in late June and early July 1922, then performed the first water ski jump in 1925.