My husband, Bernard Lucas, was in Marks-Nathan until 1942 when he graduated HS and went into the army. His younger sister & brother were also there.
Contact Faivel Berns, a Chicago attorney, who has all the records of the "kids" in Marks-Nathan OR the Jewish Children's Bureau at 1 S.Franklin St., Chicago. They should have lots of info about the orphanage.
A few years ago, there was a reunion and 600 people were there. Good luck.