Peter Cooper had erected a rolling mill…

Peter Cooper had erected a rolling mill and an iron mill in New York City, where he was the first to successfully use anthracite coal to puddle iron.

In 1845, he moved his machinery to Trenton, New Jersey, where he built the largest rolling-mill in the United States for producing railroad iron.

Here, in 1854, he had overseen the production of the first structural wrought iron beams.

Cooper introduces the Bessemer process to American steelmaking in 1856.