The Castro first gained notoriety as a Gay Mecca following the famous “Summer of Love” (which occurred in neighboring Haight Ashbury in 1967), although certainly its history goes further back than the 1960s.
Eureka Valley Gets Connected.
The Castro neighborhood (the area bordered by Diamond Heights, Noe Valley, the Mission, the Fillmore, and the Haight districts) actually became a San Francisco neighborhood all the way back in 1887, when the Market Street Cable Railway built a line to link Eureka Valley (the area that we know as the Castro) with downtown San Francisco. That was just a couple of years before Oscar Wilde came to San Francisco (in 1889) and declared that “When people disappear, they always seem to turn up in San Francisco.” Hmmm.The Scandinavians, The Irish, and the Gays.
The Castro was affectionately referred to by San Francisco locals (between 1910 and 1920) as “Little Scandinavia” because so many of its residents were of Swedish, Norwegian, or Finnish descent, but by the 1930s, it had transitioned into a working-class Irish neighborhood. It remained an Irish neighborhood until the 1960s when it “came out” as “The Castro” we know and love today.
Making a Place for Ourselves.
The late 1960s and the early 1970s saw the Castro grow more and more visibly gay, both in terms of its businesses and its residents. While this growth was met with some resistance (Harvey Milk, who was one of the first openly gay political figures in the United States, had his Camera Store in the Castro, and organized the first Castro Street Fair in 1974 as a protest against the Eureka Valley merchants who refused to work with the LGBT businesses), the LGBT community ultimately prevailed. 
So much so, in fact, that by the late 1970s, the Castro was becoming not only a center for LGBT politics, but also a destination for gay travelers from around the world. Numerous bars, restaurants, nightclubs, shops and other businesses had opened up in the Castro by that time, and were openly catering to the ever-growing gay population in San Francisco, and to the many tourists visiting the city. It was a time of "madness and magic" in the city by the bay - a time that was forever captured by Armistead Maupin in his Tales of the City books, and a time that found itself all too tragically cut short by the advent of the AIDS crisis.
The Epidemic Comes to the Castro
The Castro neighborhood was devastated by AIDS, both because it found itself at the center of the epidemic, and because it was one of the first areas to take on heavy casualties. It was a time of great sadness as neighbors, friends and many community leaders succumbed to what was then described as the "gay plague" or the "gay cancer" while health officials wrung their hands and the Federal Government did everything in its power to ignore the growing threat to public health. The city of San Francisco began closing the city's bathhouses in an attempt to get a handle on what was then a largely unknown illness, and the folks in the Castro began pulling themselves together to support the sick and the dying. The Castro neighborhood was one of the first in the country to set up support groups, healthcare services, and safe sex programs, and its response became a template for other cities. Ever resilient, the Castro brought itself and its residents back from the devastation caused by the virus that causes AIDS, and is, today, once again a vibrant community, and a safe and open neighborhood.
