What's the origin of "y'all" in the southern US?

I've always been fascinated by the way "y'all" sounds like something you'd hear in a saloon in 1885 Texas. I'm on this chamber because I love learning the history of things, and I'm always curious about the history of words.<br><br><br>I assume the word "y'all" is some sort of combination of "you all" or something, but where did it originate? Do the Irish or Scottish have something similar that was brought over? Enlighten an ignorant European.