Abortion was apparently widely practiced in the ancient world, with mention of the procedure in some of the earliest known medical textbooks.r Physicians, as well as lay advocates, have always played an active role in social movement activity concerning abortion, sometimes promoting legal abortion, and less often, opposing it.r Today about two-thirds of the world's women live in societies where abortion is legal, but the bare fact of legality per se masks considerable differences among countries as to the availability of abortion services and the social climate in which they exist.r Compared to other advanced industrialized societies, the contemporary USA is the extreme example of a society in which an antiabortion movement arose in response to legalization and ultimately managed to become a leading force in domestic politics.r Currently, the movement for safe, legal, and accessible abortion has assumed a transnational character, with joint activities of physicians from both developing and developed countries having an important impact.