SAN FRANCISCO (AP) — The rainbow flag is so ubiquitous that it’s hard to believe it has been around for only 25 years, and that before San Francisco artist Gilbert Baker sewed the first one there was no internationally recognized symbol under which GLBT people rallied.

“Unfurling Pride,” a new exhibit that opened at two locations in San Francisco May 17, examines both the historical events behind and commercialization of this enduring emblem. It is one of several celebrations planned this year to honor “the gay Betsy Ross” and the silver anniversary of his creation.

Featuring photographs, political memorabilia and sections of the original hand-dyed banner Baker made for the 1978 San Francisco Gay Freedom Day Parade, the exhibit strives to honor the pioneers who “decided to have an identity” in the words of co-curator Paul Gabriel of the GLBT Historical Society.

Walking among the items on display at the James C. Hormel Gay and Lesbian Center at the San Francisco library, Gabriel said it can be easy to forget that Baker and his crowd inherited a mantle worn by the anti-war and civil rights movements.

Baker, a self-described “drag queen” who learned how to sew so he could make himself outfits, actually designed two versions. One was an eight-striped rainbow only, the other with a corner devoted to white stars against tie-dyed blue to mimic the American flag. (For practical reasons, the rainbow flag was downsized to six stripes in 1979.)

“Let’s face it, they were hippies,” Gabriel said. “They came over the hill from the Haight to the Castro and settled the community.”

At the same time, activists were responding to blatant homophobia in the late 1970s, including the murders of 12 gay men in San Francisco in 1976, and former beauty queen Anita Bryant’s successful effort to repeal a Florida law extending civil rights to gays the following year.

“I knew right then that this was the most important thing I would ever do, that my whole life was going to be about the rainbow flag,” Baker said in notes that accompany the exhibit.

But it wasn’t until 1979, a year after the rainbow flag’s public debut, that it was widely adopted as a gay pride symbol. Responding to the November 1978 assassination of Harvey Milk, the first openly gay member of the San Francisco Board of Supervisors, organizers of the 1979 parade chose Baker’s banner as the event’s official emblem.

“This was a grassroots community that was propelled into the national spotlight and rose to the challenge,” Gabriel said. “It came together and said let’s rally around the flag and not be beaten back into the closet.”

Gabriel said he thinks the rainbow became an icon, eclipsing lesser-known gay symbols like the Greek lambda sign and the pink triangle the Nazis used to brand gays and lesbians, because “it’s universal, it’s positive and it’s inclusive.”

Within the gay community, however, the image’s commercial appeal has become a subject of debate. Among the items on display, along with Baker’s clunky Singer sewing machine, are examples of the everyday items that have been emblazoned with rainbow colors. One of them is a T-shirt featuring a rainbow flag crossed out.

“Some people see the flag and think ‘Gay dollars, right on,’” Gabriel said. “But there are others who don’t want to go into the mainstream.

Even Baker, who never obtained a copyright for his design, sees some of the commercial uses as excessive.

“As Gilbert says, nobody is more over the rainbow than he is,” Gabriel laughed.

Baker and dozens of helpers are currently working on a 1.25-mile long version that will be unveiled in Key West, Florida, on June 15. The artist will be attending a discussion accompanying the San Francisco exhibit’s official opening June 1 along with activist Cleve Jones, who created the AIDS Memorial Quilt a decade after Baker made his first flag.