America's first gay marriage fully authorized by law took place here this morning when Tanya McCloskey, 52, and Marcia Kadish, 56, exchanged vows at the Cambridge City Hall.

"I now pronounce that you are married under the laws of Massachusetts," declared Cambridge city clerk Margaret Drury at 9:10 a.m. "You may seal this marriage with a kiss."

The newlyweds embraced and Kadish jumped up and down excitedly. "Thank you. Thank you," she said.

Not far away, at Boston's city hall, protesters knelt in prayer -- and in protest -- to mark the landmark moment.

Thomas Schem, 45, of New Bedford, Mass., said he had come to Boston to object because "as a former homosexual I may understand their feelings a bit more but I also know that it is wrong."

He held a banner saying: "Jesus, Mary and Joseph. We Pray You Keep the Family Holy."

The marriage, and hundreds of marriage licenses issued Monday, were authorized under a ruling of Massachusetts' highest court, which declared last November that denying the rights of marriage to same-sex couples violated the state's constitution.

Massachusetts Gov. Mitt Romney (R) and state legislators opposed to same-sex marriage had tried to intervene before today's date -- set by Massachusetts Supreme Judicial Court -- but had failed. They have vowed to continue the fight to overturn the court's ruling by amending the state constitution, a time-consuming process requiring a referendum.

While officials in a few other jurisdictions across the country have performed gay marriages, none have been formally authorized by either a legislature or a state high court, leaving their status in legal doubt.

Massachusetts -- at least for the time being -- remains the single state where same sex marriage is undeniably legal.

President Bush has endorsed an amendment to the U.S. Constitution banning same-sex marriage. That process too, just now beginning, could take years to be voted up or down by Congress and possibly the states.

In a statement released by the White House today, Bush once again called for Congress to act on such an amendment, which would have to be ratified by the states. "The sacred institution of marriage should not be redefined by a few activist judges," Bush said in the statement. "All Americans have a right to be heard in this debate."

The lead plaintiffs in the court case responsible for today's historic activities were among the first to obtain a marriage license in Boston.

Julie and Hillary Goodridge, partners for 17 years, were joined by their 8-year-old daughter Annie, Boston Mayor Thomas M. Menino and their lawyer as they submitted the paperwork for the license this morning at the city's Government Center.

"Once again we've broken down a barrier in the city of Boston and the state of Massachusetts," said Menino. "That's what this is all about."

"Next to the birth of our daughter Annie," said Julie Goodridge, her voice breaking with emotion, "this is the happiest day of our lives."

Asked what she would tell the smattering of protesters gathered outside, she said: "Come on over to our house for dinner and find out how normal and loving and boring we are."

The Goodridges' lawyer in the case, Mary Bonauto, agreed that it was a "historic day" but said there were still "layers and layers of discrimination" to overcome and "unfinished battles ahead."

But, she said, "we can get there."

Couples had started gathering at the Government Center early in the morning. By the time the doors opened just after 9 a.m., roughly 75 began making their way inside.

Meanwhile, McCloskey and Kadish, the first gay couple to actually marry, held hands and smiled broadly in Cambridge after taking their vows.

"I feel like a bottle of champagne, I'm so bubbly," McCloskey said.

"Could somebody take our picture," she asked, as dozens of news photographers and TV camera crews obliged.

McCloskey and Kadish had lined up outside Cambridge city hall Sunday at 8:30 p.m. to file their intention to marry. They received their papers at 1:30 a.m. and were first in line at the probate court for Middlesex County at 6 a.m. to obtain a waiver of the three-day waiting period to marry in Massachusetts.

With that in hand, the couple rushed back to city hall for the ceremony.

Kadish said she and McCloskey were "shocked" to learn they were the first. "That was never a thought in our minds," she said. "We just wanted to get here early enough so we would have the whole day free to celebrate."

McCloskey, a massage therapist, and Kadish, an employment manager at an engineering firm, have been together for 18 years. They said they had not allowed themselves to think through all the details of a wedding because they had been afraid of some legal roadblock.

Laughing as they signed the license bearing the red seal of the Commonwealth of Massachusetts, McCloskey asked Kadish, "Are we going to have a honeymoon?"

"Of course," Kadish said. They sealed the wedding with rings they had previously exchanged and are planning a big reception in June.

"What a way to celebrate the freedoms we have in this country," McCloskey said. "This country is fabulous. I'm just so proud to be a citizen of the United States of America."

Before the ceremony, Drury, the clerk, had to clear up one detail: "I have to ask you what you would like to be called: spouses or wives."

Spouses was the answer.

So Drury asked each woman if she took the other "to be your be lawful spouse."

"Yes I do," each answered.

Last night, as people lined up to file their applications for marriage licenses, there was a choir singing and a brass band playing to a jubilant crowd estimated by police to be in the thousands.

There also was a giant wedding cake donated by a local hotel.

A coalition of religious and political groups opposed to same-sex marriage has lobbied vigorously here for months in favor of a constitutional amendment defining marriage as solely a union of one man and one woman. The issue is widely expected to influence statewide elections in November.

In March, the state legislature gave preliminary approval to such a measure, but included a provision establishing civil unions for gay couples. The earliest that amendment could become law is November 2006.

The same-sex marriage controversy, now an issue in the presidential campaign, began in its most recent form in 1993, when the Hawaii Supreme Court declared that denial of marriage licenses to same-sex couples violated the state constitution.

After that, state legislatures across the country, including Hawaii's, responded by enacting laws or constitutional provisions outlawing same-sex marriages.

After the Hawaii court ruling, Congress passed the Federal Defense of Marriage Act in 1996. The act, which was signed into law by President Bill Clinton, says that no state shall be required to recognize a relationship between people of the same sex "that is treated as a marriage under the laws" of any other state. It also said that for purposes of all federal law, "the word marriage means only a legal union between one man and one woman as husband and wife. . . ."

That law does not supercede state laws, although it could create numerous obstacles when and if married gay couples try to claim federal benefits or when they move from one state to another.

During the winter, more than 4,000 marriage licenses were issued in San Francisco before the California Supreme Court ordered the city to stop the practice in March after lawsuits by the state and conservative groups. It ordered hearings within three months to decide the legality of the unions.

But California's high court did not void the licenses that San Francisco had issued as the California attorney general had requested. Rather, in its unanimous ruling, the seven-member panel said it would let those on both sides of the issue argue their case as early as May.

After the weddings began in San Francisco, the Sandoval County clerk in New Mexico issued 66 marriage licenses to gay couples before the state's attorney general issued a legal opinion stopping her.

Not long after, the mayor of New Paltz, N.Y., officiated at 25 same-sex weddings. He was charged by a local prosecutor with 19 counts of violating state law by solemnizing weddings without a proper license. New York's attorney general issued an opinion saying state law defines marriage as between a man and a woman.

In Multnomah County, Oregon, the county commissioners met privately in March and decided that the county would begin issuing marriage licenses to same-sex couples. More than 3,000 couples got married before April 20, when Multnomah County Judge Frank Bearden halted the weddings.

He recognized those that had taken place, however, and told the legislature to enact a law giving same-sex couples the same rights as married couples, or he would allow a resumption of gay weddings. The issue may go to the state Supreme Court.

Finer reported from Boston. Fred Barbash reported from Washington.