USA HISTORY

Detailed explanation-1: -The Missouri River is the longest in the United States, and Lewis and Clark traversed all 2, 341 miles of it. The Corps of Discovery followed the river northwest from St. Louis all the way to where it begins at its headwaters near Three Forks, Montana in the Rocky Mountains.

Detailed explanation-2: -On this day in May, they began navigating their boats up what was to be the nearly 2, 500 miles of this river named for the Indian nation which lived near its confluence with the Mississippi.

Detailed explanation-3: -May 14, 1804: One year after the United States doubled its territory with the Louisiana Purchase, the Lewis and Clark expedition leaves St. Louis, Missouri, on a mission to explore the Northwest from the Mississippi River to the Pacific Ocean.

Detailed explanation-4: -"The object of your mission is to explore the Missouri river, and such principal stream of it, as, by its course and communication with the waters of the Pacific Ocean, may offer the most direct and practicable water communication across this continent, for the purposes of commerce."

Detailed explanation-5: -The route of Lewis and Clark’s expedition took them up the Missouri River to its headwaters, then on to the Pacific Ocean via the Columbia River, and it may have been influenced by the purported transcontinental journey of Moncacht-Apé by the same route about a century before.