In 1865, Wild Bill Hickok killed Dave Tutt in a Missouri public square in the West’s first notable "walkdown." One hundred and twenty-nine years later, Bernard Goetz shot four threatening young men in a New York subway car. Apart from gunfire, what do the two events have in common? Goetz, writes Richard Maxwell Brown, was acquitted of wrongdoing in the spirit of a uniquely American view of self-defense, a view forged in frontier gunfights like Hickok’s. When faced with a deadly threat, we have the right to stand our ground and fight. We have no duty to retreat.