On September 14, 1936, James Watts, a neurosurgeon, performed the first frontal lobotomy on a psychiatric patient in the United States. Walter Freeman, a neurologist, assisted. The patient was a woman with agitated depression, whose family had been recommended to Freeman by Karl Menninger. They wrote afterwards telling him how pleased they were with the results. During the next 20 years more than 20,000 lobotomies were performed in the United States. In 1949 alone, the year in which Egas Moniz received the Nobel prize for developing the procedure, there were more than 5000. Today we look back on this epoch as "cruel and barbaric," to use the words of Gerald Grob, the distinguished historian of psychiatry. What happened? Why? How do we understand it today? How was it understood at the time? What can we learn from it? These are the questions that frame this study by Jack D. Pressman, a brilliant young historian of medicine who devoted the last decade of his career to this project before his sudden death on June 23, 1997.