Illinois Governor Pat Quinn's office said Thursday that he will sign a gay marriage bill into law on November 20.

The signing ceremony will take place at UIC Forum, the 22,000 square foot open space at the University of Illinois at Chicago.

“Marriage equality is coming to Illinois,” Quinn, a Democrat, said in a statement. “I look forward to signing this landmark legislation on November 20 and celebrating a big step forward with the people of Illinois.”

In 2011, Quinn signed a civil unions bill into law at an event that drew roughly 1,000 people to the Chicago Cultural Center.

The House approved the marriage bill on Tuesday with one vote to spare, following in the footsteps of the Senate, which approved the bill on Valentine's Day. A change to the law's start date – from January to June – meant a return trip to the Senate. Senate members made quick work of the measure and it was on its way to Quinn's desk within hours after the House voted.

Illinois will become the 15th state to allow gay couples to marry.