Illinois Statutes Chapter 65. Municipalities § 20/21-28. Nomination by petition

(a) All nominations for alderperson of any ward in the city shall be by petition. Each petition for nomination of a candidate shall be signed by at least 473 legal voters of the ward.

(b) All nominations for mayor, city clerk, and city treasurer in the city shall be by petition. Each petition for nomination of a candidate must be signed by at least 12,500 legal voters of the city.

(c) All such petitions, and procedure with respect thereto, shall conform in other respects to the provisions of the election and ballot laws then in force in the city of Chicago concerning the nomination of independent candidates for public office by petition. The method of nomination herein provided is exclusive of and replaces all other methods heretofore provided by law.