One lesbian couple, partners for 33 years, married on a wind-swept Cape Cod beach. Another pair wed on Boston's Beacon Hill to a jubilant chorus of "Here Come the Brides." They were among hundreds of gay and lesbian (search) couples who obtained marriage licenses Monday as Massachusetts, obeying a landmark order from its high court, became the first state to allow same-sex weddings (search).

Yet even as champagne corks popped and confetti swirled, opponents of such unions declared their determination to fight back. "The sacred institution of marriage should not be redefined by a few activist judges," said President Bush, renewing his support for a proposed constitutional ban that has been introduced in Congress.

Many of the couples who obtained marriage licenses paid a fee to waive the normal three-day waiting period, and exchanged vows as quickly as feasible. Ceremonies ranged from brisk city-hall procedures to elaborate church weddings, complete with champagne, cake and bridesmaids.

"This amazing day has finally arrived. Your actions here have opened the doors for marriage to all gay and lesbian couples," said the Rev. Mykel Johnson, who married Gloria Bailey and Linda Davies on Cape Cod's Nauset Beach.

On Beacon Hill, Julie and Hillary Goodridge were married by a Unitarian Universalist minister in the presence of joyful supporters and their 8-year-old daughter, Annie, who served as ring-bearer and flower girl. The Goodridges were the lead plaintiffs among seven couples whose lawsuit prompted the Supreme Judicial Court to rule in favor of gay marriage (search) in a landmark decision last November.

Cheers erupted and rainbow confetti showered down as the two women completed their trip to the altar, three years after a Boston city clerk rejected their first marriage license application.

"This isn't changing marriage," said Hillary Goodridge. "It's just opening the door."

The modified rendition of "Here Come the Brides" included a stanza referring to the narrow margin of the court ruling: "Long may you be/Legally free/Finally hitched by a 4-3 decree."

Only a few protesters turned out in Massachusetts cities, but some conservative leaders elsewhere expressed outrage at the developments.

"The documents being issued all across Massachusetts may say 'marriage license' at the top but they are really death certificates for the institution of marriage," said James Dobson, founder of the conservative Christian lobbying group Focus on the Family.

For all their elation, the couples who received marriage licenses still confront uncertainty.

Massachusetts lawmakers have taken initial steps toward letting voters decide in 2006 whether to ban same-sex marriages and instead define such partnerships as civil unions. It is not known how the marriages occurring between now and 2006 will be recognized if the ban is imposed.

"All along, I have said an issue as fundamental to society as the definition of marriage should be decided by the people," said Republican Gov. Mitt Romney, a gay marriage opponent.

Robyn Ochs, who wept with joy while marrying partner Peg Preble in Brookline, said the idea that their marriage might be overturned "makes me nauseous."

"But that's not something I want to think about today, because today is a day for love," she said. "It's not a day for thinking about hateful people or people that don't get it."

Romney had instructed town clerks to deny marriage licenses to all nonresident couples. However, officials in three municipalities said they would issue licenses to any couples who attested they knew of no impediment to their marriage.

In Provincetown, a gay tourist spot at the tip of Cape Cod, two Anniston, Ala., men were first in line outside the town hall. "This is the most important day of my life," said Chris McCary, 43.

In the lesbian-friendly college town of Northampton, fourth- through sixth-graders from the Solomon Schechter Day School came to City Hall to witness history in the making. "It would be ridiculous not to take advantage of this opportunity," said sixth-grade teacher Becky Lederman.

Outside the city hall annex, couples hugged, took each other's photos and indulged in cookies and mimosas. Some held "We are getting married" balloons; about a dozen lesbians gathered under an American flag and sang "Going to the Chapel."

The Massachusetts couples are now entitled to hundreds of rights under state law, such as health insurance, hospital visitation and inheritance rights. But couples still lack federal rights because federal law defines marriage as between a man and a woman.

In many towns across the country, gay-rights advocates held rallies Monday celebrating the events in Massachusetts. Elsewhere, foes of gay marriage said more states should join those which already have amended their constitutions to deny recognition of same-sex unions forged in other states.