Junior Furnace, OhioJunior Furnace is an unincorporated community in Scioto County, in the U.S. state of Ohio.HistoryThe community's namesake Junior Furnace was a blast furnace built in 1828; the name was prefixed "Junior" because the property was two years younger than nearby Franklin Furnace.Notable personThomas H. Carter, a United States Senator from Montana, was born at Junior Furnace in 1854.