Frank Dabba Smith, a California-born rabbi currently living in England, recently released a history of the Leitz family, the German founders of Leica cameras. "The Greatest Invention of the Leitz Family: The Leica Freedom Train" is an account of the efforts of Ernst Leitz II, the family’s Protestant patriarch, to establish safe emigration routes for Jews to leave Germany in the guise of Leitz employees being assigned overseas.

Employees, retailers, family members and their friends were assigned to...