Polls show voters' feelings shifting rapidly in favor of gay rights. President Barack Obama said last year he supports same-sex marriage, and in November voters in four states either approved or voted down bans on gay marriage.
Illinois wasn't the only state where supporters of legalizing gay marriage picked Valentine's Day to publicize their cause.
In Oregon, the state's leading gay-rights group formed a campaign organization to get a constitutional amendment on the November 2014 ballot. And in Minnesota, more than a thousand activists rallied at the state Capitol in support of legalizing gay marriage, just months after voters defeated a measure that would have banned it.
Opponents have said they're concerned the bill would force religious organizations to allow same-sex marriage ceremonies in their fellowship halls, parish centers, or even in their sanctuaries.
Steans has said that's not the case. But before approving the measure Thursday, the Senate attached an amendment that states no church or other religious organization may be sued if they don't allow their parishes to be used for same-sex marriage ceremonies. The amendment was an effort to further reassure Republicans in hopes of picking up at least some bipartisan support.
It worked. Sen. Jason Barickman, R-Champaign, was the only Republican to vote yes. He said he was a no vote until the amendment, which he worked on with Steans.
Barickman received a round of applause from onlookers in the Senate gallery when he stood during floor debate and explained his vote.
"I believe that the people of Illinois want our government to give individuals freedom over their life decisions," Barickman said. "We want fairness under the law, and so for me, this is simply the right thing to do."