65 ILCS 5/7-2-16

All valid ordinances or resolutions of and all valid decisions determined through a referendum of the voters in any municipality which becomes a borough of a united city, regulating or prohibiting the sale of alcoholic liquor shall remain valid, notwithstanding the formation of the union, until validly changed by a compliance with "An Act relating to alcoholic liquors," approved January 31, 1934, as heretofore and hereafter amended. The local liquor control commissioner of any municipality, which becomes a borough of a united city, shall continue as such until superseded by the mayor of the united city.