Sullivan lobbied the American Psychiatric Association and the World Professional Association for Transgender Health for them to recognize his existence as a gay trans man. 1991-07 the papers are fully processed and available for use by researchers, and a finding aid is posted on the Online Archive of California. His personal and activist papers are preserved in the institution's archives as collection no. Sullivan was a founding member and board member of the GLBT Historical Society (formerly the Gay and Lesbian Historical Society) in San Francisco. He is also credited for being the first to discuss the eroticism of men’s clothing. Lou Sullivan began peer counselling through the Janus Information Facility which was an organization that provided support for transgender issues. Sullivan was instrumental in demonstrating the existence of trans men who were themselves attracted to men. Trans male persons, and also a biography of the San Francisco trans man, Jack Bee Garland.

He founded FTM International, one of the first organizations specifically for trans male individuals, and his activism and community work was a significant contributor to the rapid growth of the FTM community during the late 1980s. Sullivan was a pioneer of the grassroots female-to-male (FTM) movement and was instrumental in helping individuals obtain peer-support, counselling, endocrinological services and reconstructive surgery outside of gender dysphoria clinics. He founded FTM International, one of the first FTM organizations, along with SHAFT in the UK and Rupert Raj's Metamorphosis in Toronto, and is largely responsible for the modern acknowledgment that sexual orientation and gender identity are totally different concepts. Louis Graydon Sullivan (16 June 1951 – 2 March 1991), better known as Lou Sullivan, was an American author and activist known for his work on behalf of trans men.

We both laughed in pleasure