Micca: I was hoping someone else would have answered your question by now.

I don't know what "balling the jack" is/was, except that it seems to be some sort of dance step.

There is a song called BALLIN' THE JACK but I think the expression is older than the song.

You'll find some discussion in that thread, but it's not very enlightening.

I do have some thoughts on the subject, and I plan to do some research and then reopen that thread. It would probably be better to discuss it there than here.