Harpers Ferry is a city in Taylor Township, Allamakee County, Iowa, United States. The population was 262 at the time of the 2020 censu…Harpers Ferry is a city in Taylor Township, Allamakee County, Iowa, United States. The population was 262 at the time of the 2020 census. Harpers Ferry was platted in 1852; it was then called Winfield. In 1860, the name was changed to Harper's Ferry.