Louis R. Fletcher was originally from Harper, Harper County, Kansas before attending the University of Kansas, Southwestern College, and finally Rush Medical College at the University of Chicago, where he earned his medical degree. He took time off during his studies to earn money through various jobs in Alaska and elsewhere, including mining, lawnkeeping, and carpentry work. He later returned to KU for postgraduate study in anatomy.

Most of Fletcher's career was spent with the United Fruit Company, working in hospitals in Panama, Guatamala, and Honduras. He also served in the Navy, including as chief of surgery at Camp White Naval Hospital in Medford, Oregon.

Through careful expenditures and saving, Fletcher accumulated over a million dollars. He donated this money to the University of Kansas, which has been used as an endowed physiology fund for a variety of research projects and the construction of the Dr. Louis R. Fletcher Research Laboratories.

[Information retrieved from University of Kansas Medical Center. Department of Molecular and Integrative Phsyiology, "Dr. Louis R. Fletcher (1892-1973)," in the 2017-2018 annual report, pages 13-14.]