65 ILCS 5/3.1-20-22
In any city of less than 100,000 inhabitants, a proposition to stagger the terms of alderpersons , with as nearly as possible one-half of the alderpersons elected every 2 years, shall be certified by the city clerk to the proper election authority, who shall submit the proposition at an election in accordance with the general election law, if a petition requesting that action is signed by electors of the city numbering at least 10% of the total vote cast at the last election for mayor of the city and is filed with the city clerk.
The ballot shall have printed on it, but not as a part of the proposition submitted, the following information for voters: one alderperson elected from each even-numbered ward shall serve a term of 2 years; one alderperson elected from each odd-numbered ward shall serve a term of 4 years.
The proposition shall be substantially in the following form:
Shall (name of city) adopt a system of staggered terms for alderpersons ?
If a majority of those voting on the proposition vote in favor of it, then at the next regular election for alderpersons one alderperson shall be elected from each even-numbered ward for a term of 2 years and one alderperson shall be elected from each odd-numbered ward for a term of 4 years. Thereafter, their successors shall be elected for terms of 4 years.
65 ILCS 5/3.1-20-22