Union Furnace is an unincorporated community in northern Starr Township, Hocking County, Ohio, United States. It has a post office with the ZIP code 43158. It is located along State Route 328, which forms the main street in Union Furnace.
Union Furnace is named for a charcoal blast furnace first built on the site in 1826 by James Rodgers, John Means, John Sparks, and Valentine Fear; it began operation in 1827 under the company Rodgers & Co.
This furnace was notable as the first charcoal blast furnace in OhioâÂÂs Hanging Rock Iron Region, pioneering industrial activity in the area.
By the 1840s, operations were reorganized under Hamilton & Co. and later Hamilton-Peebles & Co. The furnace produced up to 2.5 tons of iron per day (a strong output for the era) and even experimented with not operating on Sundays, a practice adopted between Decemberâ¯20,â¯1844, and Januaryâ¯6,â¯1847.
Ownership shifted over time until John Garrett took over in 1858, at which point the furnace and the surrounding settlement officially became known as Union Furnace.
A post office has operated at the community since 1873, solidifying Union Furnace's identity as a permanent settlement.