 The banks of the Patapsco River had been unearthed to mine for ironstone, which resulted in the displaced sand and earth being dumped into the river, affecting its navigability.In 1753 a law was enacted to prevent the further filling in of the Patapsco River's shipping channel at Elkridge Landing and up to Baltimore.Caleb Dorsey, an ironmaster aware of iron ore found in the Patapsco River valley, established Elkridge Furnace in 1751 and Dorsey's Forge upriver after 1761.