On August 11, 1803, Floyd enlisted in the
Corps of Discovery for the Lewis and Clark Expedition to explore the
Louisiana Territory.
William Clark had been a family friend and recruited Floyd, grooming him as a non-commissioned officer.
Meriwether Lewis had placed Floyd in command of the officers' quarters during their absence in
St. Louis and in April 1804, he was promoted to Sergeant. Floyd began to keep a journal on May 14, the day the expedition departed from
Camp Dubois, located along the
Wood River in modern-day
Illinois. Floyd's journal entries from early June note the beauty his saw in the landscape along the
Missouri River and on July 31, he wrote "I am very sick and have been for sometime but have recovered my health again." However, this apparent recovery was soon followed by a severe turn for the worse with Clark noting that he was "very unwell." The expedition had no dedicated doctors and Floyd was attended to by
York while the captains negotiated with representatives of the
Otoe people. Floyds last journal entry on August 18 noted that "the Grand Chief of the Otoes" had arrived at camp and that same day, Clark noted that Floyd was seriously ill. On August 20 after the expedition had reached the site of present-day
Sioux City, Iowa, Floyd died shortly after noon from
peritonitis. Clark said that Floyd had died "with a great deal of composure" and that his final words were, "I am going away. Please write me a letter." A funeral was held and Floyd was buried on a bluff overlooking the
Missouri River. The expedition named the location
Floyd's Bluff in his honor. They camped that night at the mouth of
Floyd River, "about 30 yards wide, a beautiful evening.--" Clark diagnosed the condition which led to Floyd's demise as
bilious colic, though modern doctors and historians believe Floyd's death was more likely to have been caused by a ruptured
appendix. The brief "recovery" Floyd described may have represented the temporary relief afforded by the bursting of the organ, which would have been followed by a fatal
peritonitis. If that were the case, because there was no known cure for
appendicitis at that time, he would have been no better off had he been with the best
physicians of the day. ==Legacy==