Marsha P. Johnson has been considered one of the most important activists in the confrontations with police during the Stonewall riots. In the early 1970s, Johnson and her friend Sylvia Rivera co-founded the organization Street Transvestite Action Revolutionaries (STAR); together they participated in gay liberation marches and radical political actions. In the decade In 1980, Johnson continued her street activism as a respected organizer and marshall of ACT UP. Along with Rivera, Johnson was a “mother” at STAR House, handing out clothes and food to help drag queens, trans women and young people who lived on the Christopher Street docks or at her house on the Lower East Side of NY.
In July 1992, Johnson's body was found floating in the Hudson River, not far from the West Village Pier, shortly after the Pride March. Police ruled the death a suicide. Johnson's friends and supporters said she was not suicidal, and a poster campaign later claimed that Johnson had been harassed on the day of her death near where her body was found. Demands to have the police investigate the cause of death were unsuccessful. After a strong campaign led by activist Mariah Lopez, the New York Police Department reopened the case in November 2012 as a possible homicide.