the answer is the American system promised to help transport crops to northern markets.
Collateral. You can borrow money against a house or car, but if you default and don't pay it back you will lose the house or car, or whatever you used as collateral.
A Roman legion (from Latin legio "military levy, conscription", from legere "to choose") normally indicates the basic ancient Roman army unit recruited specifically from Roman citizens. In reference to the early Roman Kingdom (as opposed to the Roman Republic or Empire), "the legion" means the entire Roman army.
