Complex sentence: By the time of the American Revolution, the area's iron industry had a total production which exceeded England's, an output that would help supply George Washington's troops with cannons, rifles, and ammunition in the Revolutionary War.
Split into simpler sentences: By the time of the American Revolution, the area's iron industry had a total production which exceeded England's. That output that would help supply George Washington's troops with cannons, rifles, and ammunition in the Revolutionary War.