As with so many cultural changes, it’s not that the practice of chlorination single-handedly transformed women’s fashion; many social and technological forces converged to make those bathing suits smaller: various strands of early feminism, the fetishizing gaze of the Hollywood camera, not to mention individual stars who wore those more revealing suits. But without the mass adoption of swimming as a leisure activity, those fashions would have been deprived of one of their key showcases. What’s more, those other explanations—as valid as they are—usually get all the press.