65 ILCS 5/2-1-6
Any existing municipality which, more than 75 years prior to July 1, 1955, changed its corporate organization under the provisions of "An Act to provide for the incorporation of cities and villages", approved April 10, 1872, but no certified copy of the entry made on the records of such municipality or county court of the canvass of the votes showing the result of the election to change its corporate organization was filed with the Secretary of State as provided in said Act of 1872 and the records of such entry have been lost or destroyed, such municipality by its chief executive officer may file with the Secretary of State and the County Recorder such secondary evidence of the holding and result of such election as may be available. Thereupon the Secretary of State shall issue a certificate of approval provided for in Section 2-1-5 and such municipality shall be considered for all purposes to have been duly incorporated as a city or village, as the case may be, since the date of such election.
65 ILCS 5/2-1-6