source: It was built in 1837 and closed down ten years later, but during the American Civil War the furnace came into use again.
target: It was built in 1837 and closed down ten years later.  However, during the American Civil War the furnace came into use again.
references: It was built in 1837 and closed down ten years later.  However, during the American Civil War the furnace came into use again.