The other day a friend and I were reconciling our memories of "shotgun" rules, the customs by which American teenagers determine who sits in the front passenger seat of a car. The concept derives from descriptions of the Old West, when armed employees rode next to stagecoach drivers.
Ironically, wikipedia suggests the term postdates Westward expansion, but it got me thinking. Cross country travel was, not so very long ago, not terribly safe. Robbery was common enough to warrant hiring armed escorts.
Of course, it's not common now. I'd rank the odds of me being robbed on a lonely Wyoming highway much lower than those of me being robbed down my block. At some point, travel got safer, which can only mean banditry became ineffective or unprofitable. When did Americans become safe from highway robbers, and how did that safety come about?