Crime was an every day national threat in every American city from the Civil War to World War I. In New York, Baltimore, Chicago and Boston, people were afraid to walk the city streets after dusk. Citizens would be robbed, or they would completely disappear, and gunmen would fight daily battles, right there in the open streets. One of the most lucrative forms of crime was a train robbery, and the only law enforcement able to stem the tide of lawlessness were the Pinkertons...