Born in Pittsburgh, PA in 1919, O'Hair was called by Life Magazine in 1964 "the most hated woman in America." Forced by lack of new reading material to read the Bible cover-to-cover at age 13, she was overwhelmed by the violence and cruelty she found in the Bible stories. She gradually became an atheist in thinking, and when her son Bill objected to school prayers in the Baltimore, Maryland school system, she took the case to the Supreme Court. In a landmark decision (Murray v Curlett, 374 US. 203), she won, in her words, the "unalienable right to freedom from religion as well as freedom of religion. "

Coming to nationwide attention due to the publicity surrounding the court case, O'Hair founded "Other Americans," an organization which would later be re-named "Society of Separationists" and still later "American Atheists, Inc."

Suffering years of social harrassment and physical persecution, the O'Hair family slowly built the American Atheist organization against enormous pressure. Son William O'Hair, inspiration for the Supreme Court case, became a Christian in 1980 and later an evangelist, receiving a great deal of media attention speaking out against his mother and her organization and beliefs.

O'Hair, her son Jon Garth Murray, granddaughter Robin Murray-O'Hair, and a large sum of money belonging to American Atheists, Inc. disappeared and haven't been seen since August or September of 1995. After three years of rumor and speculation that the American Atheists were hiding the fact of O'Hair's illness or demise because she didn't want to be prayed over by Christians, or that the three family members had taken the money and absconded to New Zealand, former American Atheists member and Austin, Texas office manager David Waters and his former prisonmate Gary Karr were arrested March 24, 1999 and were ultimately charged in December, 1999 with conspiracy to kidnap and with extortion. No murder charges have been filed as of yet, and no bodies have been recovered.