410 ILCS 530/3
The Department shall search its files of records of marriage, dissolution of marriage or declaration of invalidity of marriage upon receipt of a written request and a fee of $5, and, if the record is found, shall verify the fact of marriage, dissolution of marriage or declaration of invalidity of marriage in writing to the applicant, and shall notify the applicant of the place where the original record is found, and that a certified copy thereof may be obtained only from such office. The Department shall not furnish a certified copy of the records filed with it under this Act except upon order of a court or upon the request of the clerk of any court in this State, in which event the Department shall furnish such certified copy without charge.
Whenever a certified copy is obtainable under this Section a certified computer print-out of such record shall have the same effect as a certified copy of such document.
The Department may authorize the use of the records filed under this Act and the information therein contained for any bona fide research purpose in the public interest. The Department is authorized to furnish information from, or transcripts of, its records to the United States Government for national statistics of marriage, dissolution of marriage and declaration of invalidity of marriage, provided that such is done without cost to the State.
410 ILCS 530/3