Why was it called bootlegging?

Why was it called bootlegging?
It was really named for a certain bottle used by a Canadian/American brewery. Women typically wore long gowns, and the bottle was concave. Women involved in bootlegging strapped the bottles to their thighs and it was virtually invisible.Men would slip it in the looser pockets of the time, and with the bottle shape, it hugged their leg enough to be able to slip it past police.