Bill-signing ceremonies don't generally attract large crowds, but Monday's historic signing of legislation that will allow same-sex couples to enter into civil unions is expected to bring more than 1,000 people to the Chicago Cultural Center.

Last month, lawmakers approved SB1716, the "Illinois Religious Freedom Protection and Civil Union Act." The bill allows both gay and straight couples to enter into civil unions, giving them some of the same benefits automatically available to married couples, including the right to visit a sick partner in the hospital, disposition of a deceased loved one's remains and the right to make decisions about a loved one's medical care.

Governor Pat Quinn will sign the bill into law Monday at 4 p.m., and more than 1,000 people are expected to show up at the ceremony.

"We knew there was going to be a lot of interest in participating in what is a pretty historic moment. There's only a limited number of states that allow civil unions, and a smaller amount that allow gay marriage," Quinn spokeswoman Brie Callahan told the Sun-Times. "What we wanted to do was just make it as public as we could, and the response has been overwhelming."

More than 700 people RSVP'd to attend the event within 48 hours of Quinn's office announcing the ceremony.

Chicago Mayor Richard M. Daley, Illinois Senate President John Cullerton, House Speaker Mike Madigan, Rep. Deborah Mell, Rep. Greg Harris, Sen. Dave Koehler are all expected to attend the signing, according to ChicagoPride.com. The Chicago Gay Men's chorus will perform.

"Our biggest problem right now is public response of people who want to be there to witness the ceremony. They feel this is part of history," Harris, a co-sponsor of the bill who fought tirelessly for its passage, told the State Journal-Register.

The Illinois Religious Freedom and Civil Union Act will also protect the rights of religious institutions to define marriage as they choose, and will be available to any couple, same-sex or opposite-sex, in a committed relationship who are: 18 years of age or older, not in an existing marriage or civil union, and are not related. Lawmakers hope the first civil unions can take place on June 1.

It is unclear whether any mayoral candidates are attending the signing, but more than 200 people signed up for the new LGBT and Allied Committee for Rahm Emanuel last week. Emanuel told a group of LGBT leaders that he supports full marriage rights for gay couples, and would fight for gay marriage if elected mayor.

"In the debate for civil unions, though I wasn't an office holder, I made phone calls," Emanuel said, according to ChicagoPride.com. "I look forward to making phone calls on the issue of marriage."

