Proponents of gay marriage rally outside House chambers at the Hawaii Capitol in Honolulu on Friday, Nov. 8, 2013.
When lawmakers voted this month to approve gay marriage in Illinois, the state was set to become the 15th in the nation to legalize same-sex weddings.
Now Illinois will become the 16th state.
Hawaii Gov. Neil Abercrombie signed legislation Wednesday legalizing gay marriage in that state. Same-sex marriages are set to begin in the island state on Dec. 2.
"Another universe is about to change for all time," Abercrombie said before signing the bill, comparing the legislation to Title IX, the landmark 1972 legislation that required gender equity in every educational program that receives federal funding .
Speaking before a theater of invited guests at a convention center near the tourist hub of Waikiki, Abercrombie said he believes the law is in line with the spirit of aloha embodied in the state constitution, and with the values of the monarchs who ruled Hawaii well before it became a state.
"Done," the governor said after quickly signing the measure following his speech.
Illinois Gov. Pat Quinn has said he'll sign his state's measure -- SB10 -- during a special ceremony in Chicago on Nov. 20. Gay marriages will begin in Illinois in June.
Another 14 states and the District of Columbia already allow same-sex marriage.
The Associated Press contributed to this report.