Speckledhen, you are right about ON and OWN. That is also an accent around the Knoxville area. My neighbor was born and raised around Knoxville and he says OWN for ON. I also hear other Tennesseans from Knoxville say it the same way.
My dad always pronounced Chicago as "Chicargo." His father pronounced Michigan as "Mitch-i-gain" (as in again). Where they got that, I have no idea. I do know that my mother and I mispronounce words because we either aren't interested or don't listen carefully. For example, my mother would say for BROKAW "Brokoff." Those aren't southern, just family traits, I suppose. These were smart people so it doesn't have anything to do with intelligence.
I used to hear some Jersey people say for idea "idear," and southerners would say "idee"-- as in "I have no idee." I find it interesting--I love language.
Edited because this poster can't spell, apparently. Should be "Chicago" and not Cdhicago.