"Benjamin Franklin was not a gambling man. But at the end of his illustrious life, the Founder allowed himself a final wager on the survival of the United States: a gift of two thousand pounds to Boston and Philadelphia, to be lent out to tradesmen over the next two centuries to jump-start their careers. Each loan would be repaid with interest over ten years. If all went according to Franklin's inventive scheme, the accrued final payout in 1991 would...