Is coleslaw on (rather than with) a sandwich a relatively new thing?

I have enjoyed coleslaw all my life alongside sandwiches and/or picnic-style meals (e. g., fried chicken). It is only recently that I have seen sandwiches (specifically, barbecue pork or beef) with coleslaw on the sandwich, more or less used as a condiment. Is this a new phenomenon, or is it possibly a regional specialty that has enjoyed more widespread popularity through exposure in the “info-tainmant” media?