Ai is a census-designated place[1] in Fulton County, Ohio, United States, established around 1843. The origin of its name has been a local controversy: some say that it was named after the biblical city of Ai,[2][3] while others believe that it was named after one of its founders, Ami Richards. The story continues Ami was a man, so others dropped the 'M' from his name to make the town's name more masculine.[4] Ai has been noted for its short place name.[5]
A post office was established at Ai in 1846, and remained in operation until it was discontinued in 1903.[6] With the construction of the Northern Indiana Air Line railroad during the 1850s, business activity shifted to nearby Swanton and Ai's population dwindled.[7]