“Between Thomas Edison State College and the NJ State House, a plaque reads, ‘Old Steel Mill. Here, in 1750, Benjamin Yard made steel in an iron works founded by Isaac Harrow 1733-34. The mill was on Petty's Run which now flows underground. It was one of the earliest steel mills in American and a forerunner of the great industries of Trenton.
In 1734 Isaac Harrow set up a plating and blade mill on Petty's Run, near the Old Barracks. The Run still exists but flows through a culvert under ground, emptying into the Delaware River. This mill was advertised to be sold in 1745, and Benjamin Yard became the ultimate purchaser at that time. The mill of Benjamin Yard is said to be the first steel mill in New Jersey. Mr. Yard is said to have sold these works to Owen Biddle and Timothy Matlack in 1762, and Yard appears to have erected another plating mill, which is said to have been destroyed in 1776 by the Hessians, or by the Continentals to prevent the place falling into their hands.” – Trenton Historical Society
“Petty’s Run takes its name from Nathaniel Pettit, a Quaker settler who in 1711 purchased 1400 acres of land at Trenton, including the present grounds for the New Jersey State Capitol Building.”