Official business calling him to Washington, he left St.Louis early in September, 1809, and prosecuted his journey eastward through Tennessee, by the way of Chickasaw Bluffs, now Memphis, of that State.

There is a mystery around his last days.

On the eleventh of October, he stopped at a wayside log-inn, and that night he died a violent death, whether by his own hand or by that of a murderer, no living man knows.

There were many contradictory stories about the sad affair, some persons holding to the one theory and some to the other.
He was buried where he died, in the centre of what is now Lewis County, Tennessee.

In 1848, the State of Tennessee erected over the last resting-place of Lewis a handsome monument, the inscriptions on which duly set forth his many virtues and his distinguished services to his country.
The story of the expedition of Lewis and Clark is the foundation of the history of the great Northwest and the Missouri Valley.