Abortion has been around for thousands of years.
The pro-choice movement in the United States has its roots in feminist activists, such as Margaret Sanger and others before her.
Abortion became a controversial political topic in America when major scientific breakthroughs in anesthesia and surgery occurred in the early decades of the 19th century.
These technological breakthroughs made physicians concerned because of how easy a child in the womb could be terminated.
They correctly predicted that if abortions could be done relatively safely, the stigma against the practice of abortion would decrease.
They based this prediction on parallel events going on in France, where medical breakthroughs in abortion led to social acceptance of the practice.
The majority of feminists wanted abortion to be legalized were politically associated with socialism.
For example, the feminist Stella Browne was a twentieth century socialist that was hugely influential in abortion law reform.
Browne was very influential in the United Kingdom and, beginning in the 1930s, British society saw many liberal developments in abortion law.
While Stella Browne was influencing Europe, Margaret Sanger and other feminist activists were hard at work in America.