Miles is a small city in southeastern Jackson County, Iowa, United States. The population was 408 at the time of the 2020 census. In 1870, Mileā¦Miles is a small city in southeastern Jackson County, Iowa, United States. The population was 408 at the time of the 2020 census. In 1870, Miles was founded in anticipation of a railroad which would be built through the territory. The town was named for its founder, F. M. Miles.