The two captains went to Washington early in the year following their arrival in St. Louis.  There is extant a letter from Captain Lewis, dated at Washington, Feb. 11, 1807.  Congress was then in session, and, agreeably to the promises that had been held out to the explorers, the Secretary of War (General Henry Dearborn), secured from that body the passage of an act granting to each member of the expedition a considerable tract of land from the public domain.  To each private and non-commissioned officer was given three hundred acres; to Captain Clark, one thousand acres, and to Captain Lewis fifteen hundred acres.  In addition to this, the two officers were given double pay for their services during the time of their absence.  Captain Lewis magnanimously objected to receiving more land for his services than that given to Captain Clark.

Captain Lewis resigned from the army, March 2, 1807, having been nominated to be Governor of Louisiana Territory a few days before.  His commission as Governor was dated March 3 of that year.  He was thus made the Governor of all the territory of the United States west of the Mississippi River.  About the same time, Captain Clark was appointed a general of the territorial militia and Indian agent for that department.

Originally, the territory acquired from France was divided into the District of New Orleans and the District of Louisiana, the first-named being the lower portion of the territory and bounded on the north by a line which now represents the northern boundary of the State of Louisiana; and all above that line was known as the District of Louisiana.  In 1812, the upper part, or Louisiana, was named the Territory of Missouri, and Captain Clark (otherwise General), was appointed Governor of the Territory, July 1, 1813, his old friend and comrade having died a few years earlier.

The end of Captain (otherwise Governor) Lewis was tragical and was shadowed by a cloud.  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.