Clarence Duncan Chamberlin was an American pioneer of aviation, being the second man to pilot a fixed-wing aircraft across the Atlantic Ocean, from New York to the European mainland, while carrying the first transatlantic passenger.

Denison is a city in Crawford County, Iowa, United States, along the Boyer River, and located in both Denison Township and East Boyer Township. The population was 8,373 at the time of the 2020 census. It is the county seat of Crawford County.