Explorer who became the first European explorer to cross North America from East to West above the Mexico border.
He escaped to Canada during the Revolutionary War, and secured a position with a fur trading company.
Near the completion of his journey, he left an inscription on a rock with his name and the date. That rock is now famous.
He was born into a prosperous merchant family.
His expedition took place a full ten years before that of Merriwether Lewis and William Clark.