SPRINGFIELD, Ill. — Illinois joined on Tuesday the growing ranks of states to formally sanction same-sex marriage, after a yearlong legislative showdown that invoked the Bible, the civil rights movement and competing definitions of what constitutes a family in America.

With two floor votes Tuesday and the promise of Gov. Pat Quinn’s signature, Illinois becomes the 15th state in the nation to legalize same-sex marriage — though it could fall further back in line between now and the June 1 implementation of the new law.

Reaction from around Illinois and beyond was swift.

PROMO, a Missouri gay rights organization, noted that “Missouri is now neighbored by two states in which ALL marriages are legal,” the other being Iowa. It urged supporters to use Illinois’ action to spur change in Missouri.

“Since Illinois will allow persons from out of state to marry, it is likely that many same-sex couples from Missouri will cross the state border to take advantage of this right,” said the group. “However, because of Missouri’s 2004 anti-marriage constitutional amendment, such marriages will not be recognized by the state of Missouri.”

The Catholic Conference of Illinois, meanwhile, alleged that the pending law “goes against the common consensus of the human race … (and) undermines an institution that is the cornerstone of a healthy society.”

“We remain concerned about the very real threats to religious liberty that are at stake with the passage of this bill,” the conference said in a statement.

House passage of the bill, on a 61-54-2 vote, came after months of false starts and some complicated politics. Though the Legislature is thoroughly controlled by Democrats, that majority includes rural downstate and black urban lawmakers, two blocs that have broken with their party’s general support of same-sex marriage for religious and cultural reasons.

The turn-around Tuesday reportedly came after powerful Democratic House Speaker Michael Madigan — who has supported the bill in the past, but too tepidly in the view of some gay-rights advocates — took a more active role in rounding up votes.

“The history of civilization is the history of people finding each other,” Madigan told the chamber.

The bill’s sponsor, Democratic state Rep. Greg Harris, is one of several openly gay members of the state Legislature. “What same-sex couples in Illinois want for their families is just what you want,” he told his House colleagues before the vote to approve the measure.

Harris invoked the American civil rights and women’s rights movements. “We find ourselves at another one of those moments today.”

Opponents argued that granting those rights to one group infringes on another: religiously opposed Illinoisans who, some fear, will eventually be forced to accept gay marriage in their businesses and churches or face lawsuits.

“This country was built on freedom of religion, not freedom from religion,” said Republican state Rep. Jeanne M. Ives. She predicted that “conservative people of faith will lose religious rights” under the new law.

The Senate, which first passed the bill back in February, quickly passed it again later Tuesday to concur with House amendments.

Quinn, who came into the House chamber to watch Tuesday’s vote, has been a vocal supporter of the measure and is expected to sign it into law soon.

“Today the Illinois House put our state on the right side of history,” Quinn said in a statement.

House floor debate turned on questions as old as the Bible, as well as more modern issues of balancing the rights and legal protections of competing constituencies — in this case, same-sex couples and conservative religious adherents.

Prior to the vote, Harris attached an amendment strengthening the right of churches and private entities to decline to host gay marriage ceremonies, to address a chief criticism of opponents: a fear that churches and other organizations that oppose same-sex marriage might end up being legally forced to host or participate in the ceremonies. Harris stressed repeatedly in floor debate that the measure contained “ironclad” safeguards to protect the right of opponents to avoid any involvement in same-sex ceremonies.

“Today there are couples who cannot get married in a church because of a prior marriage. … That’s up to the church,” said Harris. He insisted that the situation with same-sex marriages would be no different.

But opponents challenged that assertion. They pointed to disputes in other same-sex-marriage states in which, they said, caterers, professional photographers and others who work at weddings unintentionally ran afoul of discrimination laws for refusing to work at same-sex marriage ceremonies.

Other opponents argued that once society starts redefining marriage, it could go beyond just same-sex couples. “Those who support polyamory and polygamy are taking note,” Republican state Rep. Thomas Morrison warned. He called traditional man-woman marriage “the building block of civilization.”

Some opponents noted in floor debate that Illinois’ civil union statute already gives same-sex couples the same legal rights as married couples. “You already have civil unions. Let’s just leave it that at,” said Republican state Rep. David Reis.

Supporters countered that denying same-sex marriage deprives those couples of cultural legitimacy. “Separate but equal … is un-American,” said Democratic state Rep. Jehan A. Gordon-Booth.

The bill is SB10.

Distributed by MCT Information Services