Margaret Higgins Sanger (born Margaret Louise Higgins; September 14, 1879 - September 6, 1966), also known as Margaret Sanger Slee, was an American birth control activist, sex educator, writer, and nurse. Sanger popularized the term "birth control", opened the first birth control clinic in the United States, and established organizations that evolved into the Planned Parenthood Federation of America. Sanger used her writings and speeches primarily to promote her way of thinking. She was prosecuted for her book Family Limitation under the Comstock Act in 1914. She was afraid of what would happen, so she fled to Britain until she knew it was safe to return to the US. Sanger's efforts contributed to several judicial cases that helped legalize contraception in the United States.