On "riding shotgun"

So I was watching the show Top Shot on History Channel, and learned what I consider to be an interesting fact about the origin of the term "riding shotgun."

Back in the wild west, stagecoaches were primarily used to make deliveries, most of the time for mail services. Because of the perceived valuables on board, stagecoaches were prime targets for robberies. To mitigate this, the businesses would hire skilled marksmen to protect the items being delivered, and these shooters would sit next to the driver in the front of the stagecoach with shotguns (10 gauge), armed and ready to fire.

Just thought that was kinda interesting...