Legislation protecting same-sex marriages is heading to President Joe Biden's desk after the House gave it final approval Thursday. It's a monumental step in a decadeslong battle for nationwide recognition of those unions, and itreflects a stark turnaround in societal attitudes.

President Joe Biden is expected to promptly sign the measure, which requires all states to recognize same-sex marriages. It is a relief for hundreds of thousands of couples who have married since the Supreme Court’s 2015 decision that legalized those marriages and have worried about what would happen if the ruling were overturned.

The bipartisan legislation, which passed 258-169 with almost 40 Republican votes, would also protect interracial unions by requiring states to recognize legal marriages regardless of “sex, race, ethnicity, or national origin.” After months of negotiations, the Senate passed the bill last week with 12 Republican votes.

House Speaker Nancy Pelosi, who presided over the vote as one of her last acts in leadership before stepping aside in January, wiped her eye as she became emotional before signing the bill, which sent it to the White House immediately after the vote. She called the bill “a glorious triumph of love and freedom.”

Democrats moved the bill quickly through the House and Senate after the Supreme Court’s June decision that overturned the federal right to an abortion. That ruling included a concurring opinion from Justice Clarence Thomas that suggested the 2015 Obergefell v. Hodges decision legalizing same-sex marriage could also be reconsidered.

The legislation would not require states to allow same-sex couples to marry, as the Supreme Court's 2015 Obergefell v. Hodges decision now does. But it would require states to recognize all marriages that were legal where they were performed and it would protect current same-sex unions if the Obergefell decision were overturned.

While it's not everything advocates may have wanted, passage of the legislation represents a watershed moment. Just a decade ago, many Republicans openly campaigned on blocking same-sex marriages; today more than two-thirds of the public support them.

Democrats in the Senate, led by Wisconsin's Tammy Baldwin and Arizona's Kyrsten Sinema, worked with supportive Republican senators to address those GOP concerns by negotiating changes to clarify that the legislation does not affect the current rights of private individuals or businesses. The amended bill would also make clear that a marriage is between two people, an effort to ward off some far-right criticism that the legislation could endorse polygamy.

In the end, several religious groups, including The Church of Jesus Christ of Latter-day Saints, came out in support of the bill. The Mormon church said it would support rights for same-sex couples as long as they didn’t infringe upon religious groups’ right to believe as they choose.

Republican Sen. Susan Collins of Maine, who led negotiations with Baldwin and Sinema in the Senate, attended a ceremony after the House vote with Pelosi and House Majority Leader Chuck Schumer.