Jacques Marquette and Louis Jolliet were the explorers who traveled the Mississippi River in 1673.

In 1673, French explorers Jacques Marquette, a Jesuit priest, and Louis Jolliet, a fur trader, became the first known Europeans to travel the Mississippi River. They embarked on an expedition to map the river and explore its potential for trade routes. Their journey was significant for expanding European knowledge of the Mississippi River's path, contributing to the future colonization and development of the region by the French.