Hundreds of gay couples from across the US have been racing to get married in San Francisco after the city's mayor lifted a state ban on same-sex unions.
It was a day of celebration for gay couples
The city hall said it had married some 900 gay couples over the past three days and expected to issue hundreds more licences for wedding ceremonies.
Mayor Gavin Newsom took the decision on Thursday on the grounds that the ban was a form of discrimination.
A legal challenge to the move by anti-gay-groups is to be heard on Tuesday.
No US state allows same-sex marriage, however, San Francisco has long been a pioneer in gay rights legislation.
The mayor's decision puts officials centre stage in an intensifying national debate over same-sex marriage, the BBC's David Willis in California says.
President Bush is among those opposed to it, and it is thought he may soon endorse a constitutional amendment banning gay marriage, our correspondent adds.
News of the mayor's decision to issue marriage licences to gay couples prompted hundreds to converge on city hall.
The mayor said he was confident he would win the legal battle
The first in the line were Phyllis Lyon, 79, and Del Martin, 83, who celebrate 51 years together on Valentine's Day.
They became the first same-sex couple in America to wed legally.
"Couples are coming from as far away as New York and Minnesota to be married here," San Francisco's City Hall official told the AFP news agency.
"We married 87 couple on Thursday, 590 yesterday (Friday) and at least 200 today (Saturday) so far," the official said.
Gay couples accompanied by their friends had been waiting for hours to get married - as queues stretched several blocs away from the city hall.
The authorities were forced to bring in extra staff to cope with the demand.
The mayor's decision was hailed by gay couples around America, many of whom rushed to San Francisco.
"We found out from our friends (on Thursday) afternoon and flew up from Los Angeles last night as soon as we could," Wendy Higgins-Goodell was quoted as saying by Reuters news agency.
"We've waited 13 years for this," added Ms Higgins-Goodell, as she was holding the daughter her partner Tristan gave birth to last year via artificial insemination.
The weddings went ahead after San Francisco Superior Court Judge James Warren denied injunctions sought by conservative groups to block same-sex unions.
The groups were told to refile their lawsuits on Tuesday, as the judge said did not give a required 24-hour notice to the San Francisco attorney's office.