Margaret Sanger was an American social reformer and activist born in 1879. She is best known for her role in the birth control movement, advocating for women's reproductive rights and access to contraception. Sanger founded the American Birth Control League in 1921, which later became the Planned Parenthood Federation of America. Sanger's efforts were driven by her belief that women should have control over their own bodies and reproductive choices. She faced significant opposition during her lifetime, but her work laid the foundation for modern discussions about family planning and women's health rights.