On May 1, 1915, with WWI entering its tenth month, a luxury ocean liner as richly appointed as an English country house sailed out of New York, bound for Liverpool, carrying a record number of children and infants. The passengers were surprisingly at ease, even though Germany had declared the seas around Britain to be a war zone. For months, German U-boats had brought terror to the North Atlantic. But the Lusitania was one of the eras great transatlantic...