First European Exploration of the Mississippi: Marquette & Jolliet (1673)

In 1673, French Jesuit missionary Jacques Marquette and French-Canadian fur trader Louis Jolliet became the first Europeans to systematically explore and document the upper Mississippi River.

The Expedition

• Departure: May 17, 1673, from St. Ignace (Mackinac Strait, Michigan).
• Route: Lake Michigan → Green Bay → Fox River → portage (1.5 mi) → Wisconsin River → Mississippi River.
• Southward journey: ~1,500 miles (2,400 km) to the mouth of the Arkansas River (near present-day Arkansas City, AR).
• Turnaround: Learned from Quapaw that river led to Spanish territory (Gulf) — risked capture; turned back.
• Return: Up Illinois River → Chicago Portage → Lake Michigan → Green Bay (Sept 1673).

Significance

• Confirmed Mississippi flows to Gulf of Mexico (not Pacific or Atlantic directly).
• Mapped major tributaries (Wisconsin, Illinois, Missouri, Ohio, Arkansas).
• Established French claim to Louisiana (entire Mississippi basin).
• Opened fur trade network — basis for New France's interior economy.

Earlier Spanish Contact

Hernando de Soto (1541) crossed the Mississippi near Memphis — but did not explore its course. Álvar Núñez Cabeza de Vaca (1528–1536) may have reached its delta. Marquette & Jolliet provided the first detailed European account of the river's upper reaches.

Later: La Salle (1682)

René-Robert Cavelier, Sieur de La Salle, completed the descent to the Gulf, claiming "Louisiane" for France — building on Marquette & Jolliet's foundation.