Clark was born in 1875 to Edward Perkins Clark and Catharine Pickens Upson. Throughout his life he was the author of many books on a variety of subjects. Among them was the history of West Indies by Antonio Vázquez de Espinosa translated into English, and the modern history of Romania.
He also collaborated with the American School of Classical Studies in Rome, where he held a directory of Classical Studies and Archaeology since 1910. He died in 1960.
- "The Text Tradition of Ammianus Marcellinus", 1904
- "Greater Roumania", Dodd, Mead and Company, 1922. Chapter X
- "Bessarabia, Russia and Roumania on the Black Sea", Dodd, Mead and Company, 1927. Electronic Text Archive
- "Kate Upson Clark, Author, Dies At 83; Mother of Three Well Known Men Also Was Civic Leadert Editor and Lecturer". The New York Times. February 18, 1935. Retrieved 2010-10-08.
Mrs. Edwin Perkins Clark, better known by her nom de plume, Kate Upson Clark, died early yesterday at her home, 464 Clinton Avenue, Brooklyn. ... Two of her sons, John Kirkland Clark, president of the New York State Board of ...
- "El Consejo Real ..."
- "The Birth of the Romanian State"
- Charles Upson Clark at the Database of Classical Scholars
- Steven Foster, The Badianus Manuscript: The First Herbal from the Americas, 1992
- Azcatitlan Codex
- Bio info[permanent dead link]
- El Consejo Real y Supremo de las Indias: Su historia, organizacion, y labor administrativo hasta la terminacion de la Casa de Austria
- The Birth of the Romanian State
- Society of Fellows, American Academy in Rome