Why Is It Called A Moscow Mule And Served In A Copper Cup?

Recently I was out with co-workers and Dani, our receptionist and the gal you see when you pick up prizes at B105, ordered a Moscow Mule.  I asked what the drink was made out of and why they serve it in a copper cup.  She was able to answer one of those questions, the other spurred a table conversation.

Dani said it was a concoction of vodka,  a spicy ginger beer lime juice and garnished with a wedge of lime. It is a sometimes known as a vodka buck, but I have never heard of one of those.  It sounds tasty!  But, every single one I've seen has been served in a copper cup, why?

In a nutshell, three businessmen had product they couldn't move back in the 40's.  One was vodka, one had ginger beer he couldn't sell and one businessman had a cache of copper mugs he was sitting on.  So they combined their commodities and the Moscow Mule was born, but why the name?

According to the Huffington Post, it was born because many think of Russia when they think of vodka.  The Mule part of the name may be because ginger beer delivers a kick of flavor. However, this is speculation and not factual.