November 18, 1928 (also Minnie's). We celebrate it every year here at my house with Mickey related food (lots of cheesy things) and a special dessert usually in a mouse shape.
You'll see the number 28 on the Disney shirts w/Mickey's picture on them because that's the year he first appeared in Steamboat Willie.
Thanks. That's interesting. My son even has a shirt with 28 as the number on it, but I never knew the significance of it. Your party sounds like fun we may try it this November.