[1] In the firm of Gunn & Curtiss with Louis Singleton Curtiss he helped design several county courthouses.
Gunn's father, Otis B. Gunn, was a railroad engineer and state senator who volunteered to serve in the fourth Volunteer Kansas regiment in the Union Army during the American Civil War and served on governor Charles Robinson's staff.
[2] Gunn graduated from Rensselaer Polytechnic Institute in Troy, New York, in 1873.
[3] He formed a partnership with Curtiss in 1889 and their firm Gunn & Curtiss produced at least a dozen significant buildings over the next ten years,[4] after which he was in business alone.
[3] He died in 1959; the State Historical Society of Missouri has a collection of his and his family's papers.