Castro: from working class neighborhood to gay epicenter

Writing about Britney being in the Castro district got me thinking, how did Castro became gay? It was a working class Irish neighborhood in 1930s until mid-1960s.
The Castro became a working-class Irish neighborhood in the 1930s and remained so until the mid-1960s.

There was originally a cable car line with large double-ended cable cars that ran along Castro Street from Market Street to 29th St. until the tracks were dismantled in 1941 and it was replaced by the 24 bus.
The U.S. Military offloaded 1000s of gay servicemen in SF during WWII after they were discharged for being gay. (It's wrong but what can you do about it?) Many settled in San Francisco, and so it began the outpouring of gays to the Castro neighborhood.
It became known as the epicenter for gays during the Summer of Love in 1967. The neighborhood, which was formerly known as Eureka Valley, became known as the Castro after the theatre at Market & Castro streets. San Franciscan gays move to Polk Gulch, where the rent in low or available for purchase for low down payment in the Victorian houses, after about 1970.
You heard of Harvey Milk? Well, he would become one of the most famous residents of the Castro. While he was running a camera store, Castro Camera, he started his campaign as a gay activist.
Included in Castro at that period was the 'Castro clone,' a mode of dress & personal grooming (nowadays, it's called metrosexual) tight denim jeans, black or desert sand colored combat boots, tight T-shirt or, often, an Izod crocodile shirt, possibly a red plaid flannel outer shirt, and usually sporting a mustache or full beard—in vogue with the gay male population at the time, and which gave rise to the nickname "Clone Canyon" for the stretch of Castro Street between 18th and Market Streets. There were numerous famous watering holes in the area contributing to the nightlife, including the Corner Grocery Bar, Toad Hall, the Pendulum, the Midnight Sun, Twin Peaks, and the Elephant Walk. A typical daytime street scene of the period is perhaps best illustrated by mentioning the male belly dancers who could be found holding forth in good weather at the corner of 18th and Castro on "Hibernia Beach," in front of the financial institution from which it drew its name. Then at night, after the bars closed at 2 AM, the men remaining at that hour often would line up along the sidewalk of 18th Street to indicate that they were still available to go home with someone (aka The Meat Rack).

Here's a video clip on how Castro became the gay epicenter:

Nowadays, Castro is still C-R-A-Z-Y. You never know what you might expect, what's waiting for you at the nest corner!
So beware n' have fun! Castro is party town!
You know you're in Castro when you see the rainbow flag around. Come pride month, the rainbow flag is around every pole in SF. Being gay is accepted. Some people who live in the City for awhile have turned gay.