Early life and education
Born in Korea, Park was adopted by European American parents and raised in the United States. As a child, she attended public schools in Milwaukee. Park received a B.A. in philosophy from the University of Wisconsin-Madison, an M.Sc. in European studies from the London School of Economics and Political Science, and a Ph.D. in political science at the University of Illinois at Urbana-Champaign.
In 1997, Park co-founded Queens Pride House, a center for the LGBT communities of Queens, and Iban/Queer Koreans of New York. In 1998, Park co-founded the New York Association for Gender Rights Advocacy (NYAGRA), the first statewide transgender advocacy organization in New York.
Park was active in the coalition advocating for the transgender rights law enacted by the New York City Council (Int. No. 24, enacted as Local Law 3 of 2002). She served on the working group that helped to draft guidelines -- adopted by the Commission on Human Rights in December 2004 -- for implementation of the new statute. 
Park negotiated inclusion of gender identity and expression in the Dignity for All Students Act (DASA), a safe schools bill currently pending in the New York state legislature, and the first fully transgender-inclusive legislation introduced in that body. She also served on the steering committee of the coalition that secured enactment of the Dignity in All Schools Act by the New York City Council in September 2004. In 2005, Park became the first openly transgendered person chosen to be grand marshal of the New York City Pride March, the oldest and largest pride event in the United States.