Peter Grubb (c.1702—1754), the founder of the Grubb Family Iron Dynasty, discovered Cornwall Iron Mines and established Cornwall Iron Furnace, together one of the largest ironworks in Colonial Pennsylvania. The Cornwall Iron Mines are the largest U.S. iron mines ever discovered east of Lake Superior. In 1745 Peter decided to relinquish direct control of the ironworks, and he leased the operation to Cury and Company for 20 years at £250 a year. He moved with his wife to Wilmington, Delaware, where he engaged in the buying and selling of real estate and lived out his life.