Published: Jul 15, 2010 11:34 AM EDT
Updated: Jul 15, 2010 8:34 AM EDT

BUENOS AIRES, Argentina (AP) - Argentina legalized same-sex marriage Thursday, becoming the first country in Latin America give gays and lesbians all the legal rights that marriage brings to heterosexual couples.

After a marathon debate that lasted more than 16 hours, the vote was 33 in favor, 27 against and 3 abstentions in Argentina's Senate. Since the lower house already approved the bill and President Cristina Fernandez is a strong supporter, it now becomes the law of the land.

The bill passed despite a concerted campaign by the Roman Catholic Church and evangelical groups, which drew 60,000 people to a march on Congress earlier this week.

As debate dragged into the wee hours, supporters and opponents held rival vigils throughout 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, usually a loyal supporter of the president who gave a passionate speech against gay marriage.

But Sen. Norma Morandini, another member of the president's party, compared the discrimination that 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. The proposed law broadly declares that "marriage provides for the same requisites and effects independent of whether the contracting parties are of the same or different sex."