Margaret Sanger was a pioneering birth control activist and social reformer in the early 20th century. She opened the first birth control clinic in the United States in 1916 and was subsequently jailed for breaking obscenity laws. However, her activism helped change laws to allow doctors to prescribe contraception. In 1921, she established the American Birth Control League, a precursor to Planned Parenthood. She also worked internationally to expand access to birth control and established the International Planned Parenthood Federation in 1952. Her efforts helped make "the pill" a reality in 1960, greatly advancing women's reproductive rights.