Having lived in the north, then on the West Coast, then the South and then the North and then the Midwest I've had a little moment of 'hmph' enter my head. (You know, when you talk to yourself and you think of something and then say "hmmmmph, I didn't realize that before" happen).
I do believe that no matter where you are 'in the South', if you are in a crowd of at least 20 people that include parents and young boy-children you could call out "Little Man!" and at least 4 little guys would answer.
They don't do that in the North or the West Coast. Little guys are often called "Buddy" as in 'hey buddy did you get a new puppy?' or 'hey bud, time to come in for dinner' but down south any boy child under the age of 4 seems to answer to "Little Man".
We don't call our kids that up here. Hmmmmph.