The Halloween Parade and Mermaid Day Parade -- now major civic celebrations -- began with some arty individuals throwing jovial public parties in a city thirsty for spectacle and celebration.

Yet another community bash representing the crazy quilt of creative, community-minded New Yorkers is the St. Pat's For All Parade that winds through Sunnyside and Woodside in Queens this Sunday.

"It's like a Mardi Gras," said Brendan Fay, an Astoria activist and filmmaker originally from Ireland who helped start the "all volunteer, totally low-budget parade" 16 years ago.

Fay, who founded The Lavender and Green Alliance in New York in 1994 and married his husband, Dr. Tom Moulton in Toronto in 2003, wanted an event celebrating Irishness that included Irish gay, lesbian, bisexual, transgender and queer (GLBTQ) people who had been consistently been refused the right to march under their own banners in the St. Patrick's Day Parade on Fifth Ave.

While the event was created to assure GLBT people -- and especially GLBT young people -- they were cherished and loved in the Irish community, the Irish welcome was extended into an embrace of, well, everyone.

More than 2,000 participants and up to 10,000 spectators are expected at the wearin' o' the green -- and the rainbow -- this Sunday.

Kerry Kennedy, president of the Robert F. Kennedy Center for Justice and Human Rights, and the actor Brian F. O'Byrne, are co-grand marshals.

The pageant of 70 different groups includes stilt walkers, puppeteers, drag queens, Girl Scouts, marching bands and pick-up jams, members of a Jackson Heights mosque, Jewish members of the Irish Parliament, Episcopal Franciscans and Mexican folk dancers. Gilbert Baker, the artist who created the rainbow flag in the 1970s brings a banner as wide as a city street inscribed with a message of tolerance. (Rainbows, astonishingly prevalent in Ireland, were eventually adopted as a symbol of gay pride and diversity.) City Council Speaker Melissa Mark Viverito and Public Advocate Letitia James, Ciry Comptroller Scott Stringer and a cavalcade of other local pols join the pageant. Mayor Bill de Blasio -- a long time participant -- is expected, though he has yet to confirm.

Assembly and remarks are at 1 p.m. at 43rd St. and Skillman Ave.Participants step off at 2 p.m., ending up 56th St. and Skillman Ave. The Irish, a sentimental people, have famously long memories for noble behavior in trying times. Irish gratitude to the Choctaw Nation, which sent the Irish money in 1847 during the Irish famine, will be on parade Sunday. Tribute will also be paid to abolitionist Frederick Douglass, who spent time in Ireland in the 1840s, exchanging info with Irish freedom fighters. Douglass,who gave speeches in Ireland, wrote admiringly of Irish hospitality, marveling at the "total absence of all manifestations of prejudice against me, on account of my color."

People visit from Ireland to attend the melting pot parade. The St. Pat's for All Parade is more Irish than the Fifth Avenue version, argued Brian Fleming, an incidentally heterosexual bodhran player (Irish drummer) who flies in from County Clare each year to participate: Ireland's famous tourism slogan is "Land of a Thousand Welcomes," and "we're very proud of our reputation" of being as warm and welcoming, just like St.Pat's for All, Fleming said.

Gay and lesbian groups march in all the major St. Patrick's Day parades in Ireland "and some of them even win prizes," for their floats, explained the 45-year-old. A national referendum for marriage equality in Ireland -- with broad public support -- will be voted on in May, he added. And Queens, the most diverse place on the planet, reflects Ireland's increasing diversity as well.

St. Pat's for All was founded in the midst of civil rights controversy, so it is perhaps unsurprising that struggles endure. "The MTA is creating hell for us!" moaned Fay. The transit agency has refused to suspend scheduled repairs on the No. 7 line this Sunday, claiming expected ridership is insufficient to justify an alteration of the repair schedule. This will require workarounds for many planning to get to the parade via public transportation.

There is also dissent as to whether the Fifth Ave. parade is actually now inclusive: Organizers of the Manhattan parade are permitting a group of NBC employees to march under their banner, "Out@NBCUniversal." (NBC executive Francis X. Comerford, the grand marshal in 2012, is a trustee for The St. Patrick's Day Parade and encouraged the group to apply.)

"We felt it was important that the ban be broken and didn't want to miss that opportunity," said Craig Robinson, executive vice president and chief diversity Officer for NBCUniversal. "We understand that this isn't a perfect solution but sincerely hope that this is a significant step toward a more inclusive parade next year."

Fay and his friends still plan to variously boycott and protest the Fifth Avenue fete until GLBT Irish people are permitted to march proudly while proclaiming who they are.

Should the day of acceptance come for Irish GLBT folks to be fully accepted by the Fifth Ave. crowd, the Queens parade will continue, Fay vowed. "We get hugs!" from bystanders who are thrilled to see a celebration of so many different people "being human together," as Fay puts it. "I can't tell you how many people beg me, 'please keep up this parade!'"