http://america.aljazeera.com/articles/2013/11/20/illinois-legalizesgaymarriage.html
Source: Al-Jazeera (America) No author listed

Illinois Gov. Pat Quinn signed legislation Wednesday allowing same-sex weddings starting this summer, making [Illinois] the 16th overall [. . . ] to legalize gay marriage.

When the law takes effect June 1, same-sex couples can begin applying for marriage licenses.