Pennsylvania has been known as the "Keystone" "State" since 1802, based in part upon its central location among the original Thirteen Colonies forming the United States, and also in part because of the number of important American documents signed in the state (such as the Declaration of Independence). It was also a keystone state economically, having both the industry common to the North (making such wares as Conestoga wagons and rifles) and the agriculture common to the South (producing feed, fiber, food, and tobacco).