Senators voted 34-21 to approve the measure, sending it on to the state House where Democrats also hold a majority. Gov. Pat Quinn, a Chicago Democrat, has said he will sign the bill if the House approves it.
Jeffrey Zacharias and Bradd Easton have lived together for nine years. They hope the marathon struggle to legalize same-sex marriage is in the home stretch in Illinois.
"We want the same legitimacy as other couples and to be afforded that same right," said Zacharias.
The men already are joined in a civil union. They want their 16-year-old daughter from Easton's first marriage to understand the lifelong commitment of their relationship.
"We've been in a civil union for over a year now, and yet it's still not clear to us or her," Easton said. "If we're not necessarily married, what are we?"
The state Senate sponsors to make Illinois the 10th state to legalize gay marriage call it a matter of civil rights, that citizens should not be denied the right to marry because of their sexual orientation.
"I am very thankful that we got such a strong showing in the Senate," said State Senator Heather Steans, (D) Chicago.
But opponents say the bill does not protect churches and religion-based institutions from civil rights lawsuits forcing them to participate in gay marriage ceremonies and/or receptions.
"The Knights of Columbus Hall should not be used for a same-sex marriage," said Thomas More Society's Peter Breen.
Before Governor Quinn can sign a gay marriage bill, the measure would have to be approved by the Illinois House where there is bipartisan resistance, especially in downstate areas.
Rev. Kenneth Giles, who opposes gay marriage, says the issue should be decided directly by voters in a statewide referendum.
"I think that the state legislators that are down there now are not speaking for the people," said Rev. Kenneth Giles, pastor of Second Mt. Olive Missionary Baptist Church.
But, gay marriage supporters say the issue is one of civil rights, not majority rule.
"If you then put it up to the popular vote, then discrimination will just continue," said Easton.
The Illinois House cannot begin considering same-sex marriage until February 19, when it goes back into session.
Right now, the measure is stalled in committee, but supporters say it is only a matter of time before Illinois becomes the 10th state to legalize same-sex marriage.