(Philadelphia)  Lilli Vincenz started demonstrating for gay rights at Independence Hall in the 1960s, when the activists had a strict no-hippies dress code: suits and ties for men, dresses or skirts for women.

The dress code won’t be the only thing that has changed when Vincenz, 71, returns to Philadelphia this weekend for the National Equality Rally. The event planned for Sunday is being billed as the first national demonstration since 2000 for gay, lesbian, bisexual and transgender rights and the first to be held outside Washington.

“We are at the tipping point of the GLBT civil rights movement,” said Malcolm Lazin, executive director of the Philadelphia-based Equality Forum, which is sponsoring the event. “This is a movement that will not let up.”

Supporters will have much to cheer. Nine years ago – before the last march on the National Mall in Washington – Vermont had just passed the country’s first civil-unions law. Today, gays can marry in Vermont, Connecticut, Iowa and Massachusetts; bills are pending in several other states.

But gay rights advocates also say there is much work to do. Demonstrators will call for same-sex marriage equality nationwide; for including transgendered individuals in federal anti-discrimination and hate crime laws; and for repealing the Defense of Marriage Act and the military’s “Don’t Ask, Don’t Tell” policy.

Organizers plan a march circling the blocks around Independence Hall and the Liberty Bell, followed by a one-hour rally.

“It is important for our community to come together to celebrate our lives and our accomplishments as well as to push for further inclusion in the nation’s promises of liberty and equality for everyone,” said Jennifer Manion, director of student services for the gay community at Connecticut College.

The symbolism of Philadelphia, where all men were declared created equal, was just as powerful to Vincenz and Frank Kameny, who organized the first “Annual Reminder Day Picket” for gay rights on July 4, 1965, at Independence Hall.

Kameny, a World War II combat veteran, said he lost his job with the U.S. Army’s map service in 1957 because he is gay. The pickets were designed “to remind the public that there’s still one large group of people who are not having their rights protected, and are still being subject to prejudice and discrimination without remedy,” he said.

Activists demanded an end to anti-gay bias in federal civil service employment and the removal of homosexuality from the American Psychiatric Association’s list of mental disorders, among other issues.

The first picket was held four years before the landmark Stonewall riots in New York, considered the birth of the gay rights movement. It drew between 25 and 40 people, according to Kameny and Vincenz. By the time the fifth one was held in 1969, just as Stonewall was ending, about 150 people attended.

Today’s gay rights rallies, which can draw tens of thousands, involve issues “we never would have conceived back then,” Kameny said.

Now 83 and living in Washington, Kameny will return on Sunday to the site of the “annual reminders,” which are now commemorated by a state historical marker.

By any measure, the gay rights movement has achieved “remarkable success” in the 40 years since Stonewall, Manion said. But those victories mask deeper-rooted problems with homophobia, especially as experienced by adolescents too young to benefit from same-sex marriage or job anti-bias laws, she said.

“Young people … are still subject to the beliefs and whims of their parents,” Manion said. “All the stigmas are still the same.”

Vincenz, though, said she is optimistic about the future. She looks forward to visiting Philadelphia for the march and rally – while wearing a pair of “nice slacks.”

“I just feel ecstatic about the younger generation and what they’re doing,” Vincenz said. “There’s a groundswell of people who finally feel empowered, that they can make a difference.”