After the iron works closed, the site fell into disuse and became hidden by underbrush. In 1898, the Lynn Historical Society erected a historical marker near the site which read "The First Iron Works. The first successful iron works in this country established here. Foundry erected in 1643. Joseph Jenckes built a forge here in 1647 and in 1652 made the dies for the first silver money coined in New England. In 1654 he made the first fire engine in America." Eventually, the plaque too became obscured by the underbrush and remained camouflaged until it was discovered during the restoration of the Iron Works.