In 1877 former president Ulysses S. Grant, along with family and friends, embarked on a two-year world tour that took him from Liverpool to Yokohama with stops throughout Europe and Asia. Biographies of Grant deal very briefly, if at all, with this tour and generally treat it as a pleasure trip filled with sightseeing, shopping, wining, and dining. Far from an extended vacation, however, Grant's travels in fact constituted a diplomatic mission sanctioned...