While no single document can capture the full history of America's largest rivers, here is an overview of the key historical roles and events associated with the top 10 rivers by length and volume.
Missouri River (2,540 miles)
Longest river by length
Early exploration: In 1673, French explorers Jacques Marquette and Louis Jolliet were the first Europeans to encounter the river, and the Lewis and Clark Expedition (1804–1805) was the first to navigate its full length.
Native peoples: The river was home to Indigenous nations such as the Blackfeet, Hidatsa, and Crow for millennia, and later became a major thoroughfare during European contact and westward expansion.
Name origin: The river was named after the Missouria tribe. It was also nicknamed "Big Muddy" for the amount of sediment it carried.
Commerce: French fur traders began navigating the river in the 1700s, and steamboat traffic flourished in the 1800s before declining with the advent of railroads.
Modern control: Extensive flooding in the mid-1900s led to the construction of numerous dams, profoundly changing the river's character.
Mississippi River (2,340 miles)
Largest river by volume
Geological history: The river's current course was shaped by glacial meltwater, with its delta formed over thousands of years.
Indigenous peoples: Thriving Indigenous cultures lived along the river for centuries, with the fertile lands supporting agriculture. The river's name comes from the Ojibwe phrase "Misi-ziibi," meaning "Great River".
European powers: The river served as a border between French and Spanish territories before the Louisiana Purchase in 1803.
Steamboat era: The 19th century saw a boom in steamboat traffic, and cities like St. Louis, Memphis, and New Orleans grew into major commercial centers.
Civil War: Control of the Mississippi was a strategic objective during the Civil War, with Union forces capturing it in 1863.
Modern engineering: Extensive engineering works, including locks and dams, have been built to control the river's flow and prevent it from shifting its course to the Atchafalaya River.
St. Lawrence River (744 miles)
Largest by volume (partially in US)
Exploration and settlement: Explored by Jacques Cartier in 1534, the St. Lawrence was the gateway for French colonization of North America.
Trade and conflict: It served as a critical route for the fur trade, later becoming a contested area during conflicts between Britain and France.
Seaway: The St. Lawrence Seaway, constructed in the 1950s, allows oceangoing vessels to travel from the Atlantic Ocean to the Great Lakes, boosting trade.
Ohio River (1,310 miles)
Indigenous history: The river was a major trade and transportation route for Native Americans for thousands of years. The name "Ohio" comes from the Seneca word for "Good River".
Westward expansion: It became a primary route for pioneers during America's westward expansion in the late 18th century.
Civil War: For part of its length, the river served as the border betwee
