Governor Pat Quinn is pledging to keep working with Illinois lawmakers to legalize same sex marriage.
Quinn called Wednesday’s Supreme Court rulings a "monumental day for freedom." The court struck down part of a law that denied federal benefits to legally married gay couples.
Illinois allows same sex couples to enter into civil unions, but the state has yet to allow same sex marriage.
Those pushing for Illinois to legalize same sex marriage point out there are approximately 1,100 federal benefits that are granted only to people who are married. Those who are in civil unions are not eligible.
The effect of the Supreme Court's decisions is more complex when it comes to gay and lesbian couples who married in states such as Iowa, where same sex marriage is legal, but who live in Illinois.
Christopher Clark, an attorney for the gay rights group Lambda Legal, said those couples will receive some of the federal benefits of marriage, but not others.
“I think we're going to need some clarification probably from the Obama administration and various federal agencies as to how they're going to interpret their practices going forward,” Clark said.
Clark said given that President Barack Obama supports gay marriage, he's hopeful the administration will use a broad definition.
A bill that would have legalized same sex marriage easily won approval in the Illinois Senate this year, but it never came up for a vote in the House.