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.
Missouri carried out the execution of Joseph Paul Franklin a little after 6 a.m. He was put to death after courts overturned Tuesday's stays of execution.
Yesterday, two federal judges issued stays of execution.
The judges took issue with how the state was getting its lethal injection drug from a secret source not regulated by the Food and Drug Administration, and questioned whether the inmate was mentally competent to be executed.
The state of Missouri, led by Attorney General Chris Koster, appealed quickly.