Illinois was the first state to repeal state sodomy laws - the new state code passed on 28 July 1961 and became effective 1 January 1962.
In 1996, the Illinois Marriage and Dissolution of Marriage Act was amended to prohibit marriage between two individuals of the same sex and stated that "marriage between 2 individuals of the same sex is contrary to the public policy of this State".
Attempts to add language banning same-sex marriage to the state constitution were not successful in IL.
Illinois provided benefits to same-sex partners of state employees beginning in 2006.
February 2007, Representative Greg Harris introduced the Religious Freedom and Marriage Fairness Bill in the Illinois House of Representatives, which would have provided for same-sex marriage in the state. The bill died in committee.
From January 2009 to January 2013, Representative Harris and Senator Heather Steans introduced legislation to legalize marriage equality 8 times.
On 31 January 2011, Governor Pat Quinn signed legislation recognizing same-sex civil unions performed on or after 1 June 2011. In 2012 an attempt was made to repeal this legislation, but it failed.
5 November 2013, the House of Representatives finally passed a bill (SB10) legalizing same-sex marriage by 61–54, narrowly achieving the necessary 60-votes. The state Senate quickly approved the amended bill by a 32–21 vote margin and Governor Quinn signed the bill into law on 20 November 2013.The law went into effect on 1 June 2014.