Charles M. (Charles Marcus) Horton

Charles M. Horton, identified in library records as Charles Marcus Horton (born 1879), is credited with at least two books that have remained accessible through major public-domain collections: Opportunities in Engineering and Bred of the Desert: A Horse and a Romance.

Those surviving works suggest an author with a notably wide range. Opportunities in Engineering presents engineering as a profession and a path of opportunity, while Bred of the Desert points to an interest in fiction and the landscapes of the American West.

Reliable biographical detail on Horton appears to be limited in the sources I could confirm, so it is safest to describe him as an American author active in the early 1900s whose known work spans both career-focused nonfiction and popular fiction.