Iota Sigma Pi is a national honor society for women in chemistry which began in 1902 with the organization of the Hydrogen chapter here at the University of California, Berkeley. Since the appearance of that seminal chapter, 10,000 members have been initiated into forty chapters nationwide. We promote the professional development and personal growth of women in chemistry and related fields through recognition, public outreach and the formation of supportive networks. In the late 1970's the Hydrogen chapter at Berkeley became inactive. In the spring of 1997 an effort was made to reestablish Iota Sigma Pi at the University of California, Berkeley. After several months of work the Hydrogen chapter was reactivated on Saturday, September 20, 1997 with 25 charter members. Since then the chapter membership has grown to the current level of approximately 45 women which includes undergraduate students, graduate students, professors, and professional chemists.