Argentina legalized same-sex marriage Thursday, becoming the first country in Latin America to grant gays and lesbians all the legal rights, responsibilities and protections that marriage brings to heterosexual couples.

People show a sign to support the discussion in Argentinian Senate on the approval of homosexual couples in Buenos Aires, July 14, 2010. Argentina became the first Latin American country to recognize by law marriages between homosexual people Thursday. [Telam/Xinhua]

After a marathon debate, 33 lawmakers voted in favor, 27 were against it and 3 abstained in Argentina's Senate in a vote that ended after 4 a.m. Since the lower house already approved it, and President Cristina Fernandez is a strong supporter, it now becomes law as soon as it is published in the official bulletin.

The law is sure to bring a wave of marriages by gays and lesbians who have increasingly found Buenos Aires to be more accepting than many other places in the region.

The approval came despite a concerted campaign by the Roman Catholic Church and evangelical groups, which drew 60,000 people to march on Congress and urged parents in churches and schools to work against passage.

Cardinal Jorge Mario Bergoglio said "everyone loses" with gay marriage, and "children need to have the right to be raised and educated by a father and a mother."

Nine gay couples had already married in Argentina after persuading judges that the constitutional mandate of equality supports their marriage rights, but some of these marriages were later declared invalid.

As the debate stretched on for nearly 16 hours, supporters and opponents of held rival vigils through the frigid night outside the Congress building in Buenos Aires.

"Marriage between a man and a woman has existed for centuries, and is essential for the perpetuation of the species," insisted Sen. Juan Perez Alsina, who is usually a loyal supporter of the president but gave a passionate speech against gay marriage.

But Sen. Norma Morandini, another member of the president's party, compared the discrimination closeted gays face to the oppression imposed by Argentina's dictators decades ago.

"What defines us is our humanity, and what runs against humanity is intolerance," she said.

Same-sex civil unions have been legalized in Uruguay, Buenos Aires and some states in Mexico and Brazil. Mexico City has legalized gay marriage. Colombia's Constitutional Court granted same-sex couples inheritance rights and allowed them to add their partners to health insurance plans.

But Argentina now becomes the first country in Latin America to legalize same-sex marriage nationwide, granting gays and lesbians all the same rights and responsibilities that heterosexuals have. These include many more rights than civil unions, including adopting children and inheriting wealth.

Gay rights advocates said Argentina's historic step adds momentum to similar efforts around the world.

"Today's historic vote shows how far Catholic Argentina has come, from dictatorship to true democratic values, and how far the freedom to marry movement has come, as twelve countries on four continents now embrace marriage equality," said Evan Wolfson, who runs the U.S. Freedom to Marry lobby.

He urged U.S. lawmakers to stand up "for the Constitution and all families here in the United States. America should lead, not lag, when it comes to treating everyone equally under the law."

Among the opponents were teacher Eduardo Morales, who said he believes the legislation was concocted by Buenos Aires residents who are out step with the views of the country.

"They want to convert this city into the gay capital of the world," said Morales of San Luis province.

Ines Franck, director of the group Familias Argentinas, said the legislation cuts against centuries of tradition.

Opposing the measure "is not discrimination, because the essence of a family is between two people of opposite sexes," he said. "Any variation goes against the law, and against nature."

The president, currently on a state visit to China, spoke out from there against the Argentine Catholic Church's campaign and the tone she said some religious groups have taken.

"It's very worrisome to hear words like 'God's war' or 'the devil's project,' things that recall the times of the Inquisition," she said.

Some opposition leaders have accused her of promoting the initiative to gain votes in next year's presidential elections, when Fernandez's husband, former President Nestor Kirchner, is expected to run again.

The vote came after Sen. Daniel Filmus urged fellow lawmakers to show the world how much Argentina has matured.

"Society has grown up. We aren't the same as we were before," he said.