Knowledge of how to prevent conception and birth is not a discovery of the twentieth century. Historical demographers have hypothesized that family planning was widely practiced in pre-industrial European communities. However, organized efforts to promote the practice of birth control do not seem to have emerged until the second half of the nineteenth century in England and some time later in the United States. It is important to emphasize that the birth control movement developed as a feminist or social reform movement rather than as a specific effort to control population growth. Thus, the movement founded by Mrs Sanger in the United States in 1913 maintained that women have the right to freedom from unwanted pregnancies. In the Soviet Union this liberal notion that a woman has the right of control over her own body did not lie behind the early law which legalized abortion in that country. Abortion was first legalized, on 18 November 1920, only as a necessary but temporary health measure, quite independent of family legislation. Although at that time the legalization of abortion was a pioneering step, it should be noted that its main purpose was not so much to enhance the woman's freedom of choice as to reduce the high mortality rate associated with illegal abortions. The main rationale of the decree of 18 November 1920 was to protect the life of Soviet women, not their freedom to plan the size of their family.