Ironton, a city and the county seat of Lawrence co., Ohio, on the Ohio river, 142 m. above Cincinnati, and 100 m. S. by E. of Columbus; pop. in 1860, 3,691; in 1870, 5,686. It is built above the highest floods, at the foot of lofty hills, in the centre of the "Hanging Rock" iron region, embracing a portion of S. Ohio and N. E. Kentucky, of which it is the principal business point. Its iron trade amounts to about $7,000,000 a year, and is rapidly increasing. The Iron railroad, 13 m. long, connects it with the N. part of the county. It is lighted with gas, supplied with water by the Holly system, and contains four blast furnaces, two rolling mills, a nail factory, a machine shop, a stove and hollow ware foundery, two boiler works, a hoe factory, two saw and planing mills, a boat-building establishment, a tannery, two breweries, two national banks, several graded public schools including a high school, a tri-weekly, a semi-weekly, and three weekly (one German) newspapers, and 15 churches. Ironton was laid out in 1849 by the Ohio iron and coal company, and was incorporated as a city in 1865.