O. O. (Olin Oglesby) Ellis

Born in 1886, O. O. Ellis was Olin Oglesby Ellis, a writer associated with Uvalde, Texas. Library and archive records identify him as the coauthor of The Plattsburg Manual: A Handbook for Military Training, a widely circulated guide first published during the World War I era.

Ellis worked with E. B. Garey on manuals that translated military training into straightforward instruction for civilians and trainees. His known books include The Plattsburg Manual and related training works connected with the federal training-camp movement, showing a focus on practical education rather than literary fame.

Confirmed biographical detail about his personal life is limited in the sources I found, but genealogical records list his lifespan as 1886 to 1968. What stands out most is the useful, instructional character of his writing: concise, organized, and aimed at helping ordinary readers understand military preparation in a time of national mobilization.