The modern transgender rights movement has its roots in the mid-20th century, with the work of pioneers like Christine Jorgensen, who became one of the first Americans to undergo sex reassignment surgery in 1952. The 1960s and 1970s saw the emergence of the first transgender rights organizations, such as the Mattachine Society and the Gay Liberation Front. However, it wasn't until the 1990s and 2000s that the transgender community began to gain more visibility and recognition.