Why Do We Call Dibs and Shotgun, and Who Was the Real McCoy?

Some idioms have a fairly clear origin, but others have been lost to time and legend. Learn about the game that inspired calling dibs, the media that created calling shotgun, and why the 'real' McCoy was probably a number of people -- all in today's episode of BrainStuff, based on these articles: https://science.howstuffworks.com/innovation/famous-inventors/why-do-people-call-things-the-real-mccoy.htm; https://people.howstuffworks.com/what-are-dibs-and-why-do-call-them.htm; https://people.howstuffworks.com/riding-shotgun-phrase.htm
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