 Following an explosion killing seven employees on 19 July 1828, the Gambo Falls mill was enlarged by Oliver Whipple concurrently with construction of locks for the Cumberland and Oxford Canal.Whipple had been manufacturing gunpowder in Lowell, Massachusetts since 1818.The new canal provided reliable transportation from Portland harbor for sulfur from Sicily and saltpeter from India and from Sebago Lake for charcoal and lumber from forests to the north.