A coalition of clergy members and faith leaders has sent a letter to Illinois House members encouraging them to support gay marriage.
The letter has more than 300 signatures. It says allowing same-sex couples to marry is "morally just."
The Illinois General Assembly returns to Springfield this week and supporters of gay marriage hope the House will take up the bill, which passed in the Illinois Senate on Valentine's Day.
A coalition of black ministers has strongly opposed gay marriage, including robocalls asking people to urge their lawmakers to vote against it. A lawsuit challenging Illinois' ban on gay marriage is pending in state court.