Illinois Governor Pat Quinn said Wednesday that he would this month sign legislation legalizing gay marriage in Illinois.

Quinn, a Democrat, told reporters that his office is planning to invite the numerous activists and advocates involved in lobbying for the measure to the signing ceremony.

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.