Complex sentence: Madalyn Murray O'Hair (April 13,1919--September 29,1995) was an American atheist activist; a founder of the American Atheists and its president from 1963 to 1986.
Split into simpler sentences: Madalyn Murray O'Hair (April 13,1919--September 29,1995) was an American atheist activist. She was the founder of the American Atheists and its president from 1963 to 1986.