Supporters and opponents had been working furiously up until Tuesday to line up votes on whether the state should offer some kind of legal recognition to same-sex couples.
Civil unions would provide legal recognition of gay couples and give them some of the same benefits automatically available to married couples -- the right to visit a sick partner in the hospital and make decisions about their medical care, for instance. But it would not be marriage, which is still defined by Illinois law as a union of one man and one woman.
Illinois civil unions would not be recognized in some states or by the federal government for tax purposes.
Emotions ran high during the debate.
Rep. Deborah Mell, D-Chicago, broke down as she discussed the possibility of her partner, Christin Baker, falling seriously ill. She said current law would bar doctors from consulting her about Baker's condition because they have no official recognition.
Many legislators mentioned former Rep. Larry McKeon, who was Illinois' first openly gay lawmaker. Hospital administrators turned McKeon away when his longtime partner was dying, saying he had to go home and get documents proving he had the right to visit. By the time McKeon was able to get the document and return, his partner had died.
"It's appalling that anybody would think that's OK. It's not OK," said Rep. Lou Lang, D-Skokie.
On the other side of the debate, Rep. Ron Stephens quietly insisted his opposition was based on principle, not animosity
toward homosexual people.
"Just call me an old-fashioned traditionalist,'' the Greenville Republican said.
Few lawmakers spoke against the legislation. Those who did argued civil unions are a step toward legalizing same-sex marriage, perhaps by court order.
"Are you ready for gay marriage? Because that very well could be what comes out of this," said Rep. David Reis, R-Willow Hill.
Lobbyist Rick Garcia had a response for such concerns: "You are correct."
Garcia, director of public policy for the gay-rights group Equality Illinois, said he considers civil unions a poor substitute for marriage but hopes the move eventually leads toward marriage rights for gay couples. He and other supporters say same-sex marriage has little support in the Legislature right now, so civil unions are the most they can get.
At least five states already offer civil unions. A handful of others have legalized same-sex marriages.
The Human Rights Campaign, the nation’s largest lesbian, gay, bisexual and transgender civil rights group, praised the body for passing the bill.
"HRC congratulates Illinois’ House of Representatives for recognizing that all couples and all families deserve basic rights and protections," HRC President Joe Solmonese said in a written statement. "Civil Unions are not marriage, but they provide important benefits and are step in the right direction."