The William Otis Raiguel papers span the years 1905-1932 and include correspondence, contractual agreements, travel diaries, and an insurance application. The correspondence, dated from 1909-1920, is between Raiguel and John Galen Howard, and documents some of their financial arrangements. The three travel diaries completed on his trip to England, France, and Italy include sketches of architectural plans, buildings, and architectural details. The diary from his later trip around the United States, Canada, and Europe contains small photographs, itineraries, and a few articles and brochures. The collection was donated in 1947.