765 ILCS 15/1
Whenever upon the trial of any civil action, in this State, any party to the action, or his agent or attorney in his behalf, shall by affidavit to be filed in the action, testify and state under oath that the required United States patent conveying or concerning the title to the lands, tenements and hereditaments in question in such suit is lost, or not in the power of the party wishing to use it on such trial of any such action, and that to the best of his knowledge said patent was not intentionally destroyed or lost, or in any manner disposed of for the purpose of introducing a copy thereof in place of the original, and if the original patent has been recorded in the recorder's office of the county wherein such lands are situated, then the record thereof, or a copy duly certified by the recorder in whose office the same may have been or may hereafter be recorded, may be read in evidence in any court in this State with like effect as though the original patent was produced and read in evidence.
765 ILCS 15/1