Update: As of April 1, the coalition consists of more than 200 U.S. mayors.

WASHINGTON — “Freedom to Marry,” a New York-based marriage equality advocacy organization, on Friday announced a bipartisan coalition of more than 80 mayors from across the U.S. who have publicly stated their support for marriage equality for LGBT citizens, and their intention to work toward that goal.

More than 20 of the mayors attended a morning news conference at the Capital Hilton in Washington, including the coalition’s chairpersons: New York City Mayor Michael Bloomberg (I), Los Angeles Mayor Antonio Villaraigosa (D), openly lesbian Houston Mayor Annise Parker (D), San Diego Mayor Jerry Sanders (R), and Boston’s Democratic Mayor Thomas Menino.

In a joint statement, the mayors pledged to advocate for marriage equality, and called upon mayors from across the nation to join their coalition:

Mayors for the Freedom to Marry is a broad-based and nonpartisan group of mayors who believe that all people should be able to share in the love and commitment of marriage … We understand that the strength and health of our cities are enhanced when all families are protected and supported. We know many people in loving and committed same-sex relationships who are active participants in improving our communities and we’ve seen how important marriage has been for them and their families. […] We invite our colleagues to join us in signing this statement as we advocate for the freedom to marry and build a nation where all loving couples who want to make the life-long commitment can share in the joy and respect of marriage.

Chicago’s mayor Rahm Emanuel, the former White House Chief of Staff under President Barack Obama, is among the U.S. mayors who have already signed the pledge, as did mayors representing Denver, Minneapolis, Newark, Philadelphia, Phoenix, San Francisco, Seattle, St. Louis and St. Paul.

“It was nearly eight years ago that my city was the first large city in the country to marry same-sex couples,” Menino said at Friday’s news conference.

“Back then, it was a big deal. People were protesting everywhere, and we were the focus of international news. Well, eight years later, I’m here to tell you that marriage for gay couples has made my city of Boston a much better place,” Menino said.

Watch a clip from the news conference here:

Houston’s openly lesbian Mayor Annise Parker, who recently celebrated 21 years with her partner Kathy, shared her personal story saying that denial of marriage “makes it more difficult to provide our children insurance; it makes it more difficult to assure custody and it makes it more difficult to provide them access to the benefits of our society.”

Los Angeles Mayor Villaraigosa said that Mayors should sign on to this effort because marriage discrimination harms local communities.

“Law-abiding, tax-paying families deserve the same opportunities, rights and responsibilities afforded to every other family in this country,” Villaraigosa said.

“If we truly believe in family values, we should value all families. Denying gay and lesbian couples the freedom to marry weakens society by hurting our communities, neighbors, and families,” he said.

Following is the complete list of mayors in the “Mayors for the Freedom to Marry” coalition, as of Jan. 20. (Click on list to enlarge.)

Click to enlarge.