William Chauncy Langdon (1831–1895) was a Protestant Episcopal clergyman and a prominent American proponent of the YMCA.
He founded three Episcopal Churches in Europe: Grace Church in Rome, 1859 (later renamed as St. Paul's Within the Walls); St James's in Florence, c. 1870; and Emmanuel_Episcopal_Church_(Geneva), 1873. These are now parishes of the Convocation of Episcopal Churches in Europe.
His son by the same name (1871–1947) was an historian of pageants.
General references
Esolen, Anthony. 2020. “No Option: Clear Out the Rubble & Rebuild!” Touchstone: A Journal of Mere Christianity 33 (4): 28–38. Hoefnagel, Dick & Virginia L. Close. "Charles N Haskins and the Woodward Room at Baker Library". Dartmouth College Library Bulletin. "William Chauncy Langdon." In Dictionary of American Biography. New York, NY: Charles Scribner's Sons, 1936. Gale In Context: Biography (accessed January 16, 2021). Stefano Villani, “William Chauncey Langdon e l’attività del Comitato sulla Riforma italiana della Chiesa Protestante Episcopale negli Stati Uniti d’America (1865-1874),” Protestantesimo, 73 (2018), pp. 129-186.