"In 1864, during the bloodiest days of the Civil War, two newspapers published a call, allegedly authored by President Lincoln, for the immediate conscription of 400,000 more Union soldiers. New York streets erupted in pandemonium. Wall Street markets went wild. When Lincoln sent troops to seize the newspaper presses and arrest the editors, it became clear: the proclamation was a lie. Who put out this fake news? Was it a Confederate spy hoping to...