Marmora Ironworks 1823
In 1821 an Irish immigrant, Charles Hayes, began building here one of the province's earliest smelters and foundries, which by June, 1823, was ready to produce pig iron from ore mined near present-day Blairton. Economic difficulties and transport problems soon ended Hayes' venture, but his principal creditor, the Hon. Peter McGill, continued operating it until 1826. In 1837 the government rejected a proposal to use convict labour for the works. Joseph Van Norman's attempt in 1848 to revive the enterprise was frustrated by cheaper British iron brought up the newly-completed St. Lawrence canal system. The works fell into ruin although mining was resumed, 1866-73, the ore being taken to Cleveland and Pittsburgh for smelting.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.