Ferguson, openly gay and playing the role of a gay man on the television program "Modern Family," attended an event at Chicago's James R. Thompson Center Wednesday, prior to traveling with other supporters to the state capital, Springfield, for "Bow Tie Lobby Day", where they will encourage legislators to wear bow ties Thursday in support of a marriage equality bill, the Chicago Tribune reported Wednesday.
The bill is expected to come before the Senate this week.
Ferguson's fiance, Justin Mikita, accompanied him to the event, the newspaper said.
"'Modern Family's' popularity and presence on television has helped to propel the issue of same-sex marriage, Ferguson noted.
"A lot of people who were not comfortable with marriage equality turn on the television and see a show with a lot of different families in it, and one of those families happens to be gay. They're watching a gay couple that's having a lot of the same issues and problems they have. They realize, oh, they're not so different from me," Ferguson said.