Vernita Gray (left) and her partner Patricia Ewert had a civil union in Chicago's Millennium Park in June 2011. A judge ruled Monday that they should be allowed to legally marry now because of Gray's health.
Illinois is now the 16th state to allow same-sex marriage.
Gov. Pat Quinn signed a bill into law Wednesday in Chicago that makes the state the largest in the Midwest to legalize gay weddings. The law takes effect in June when county clerks can begin issuing marriage licenses to same-sex couples.
Illinois allowed civil unions in 2011, but it was a bumpy road to same-sex marriage in President Barack Obama's home state.