Private adoptions in ILLINOIS

I was born on November 27, 1974. I was adopted through Lutheran Child and Family Services. I was born in St. Elizabeth's in Belleville Illinois. My biological mother was 18 at the time of birth and father was 20. My biological mother had major second thoughts about putting my up for adoption. My biological mother also had another baby girl she put up for adoption in 75 or 76. She was adopted to a family in the Waterloo Illinois area. I have registered with the Illinois adoption registry but no one else has registered. Any information or direction would be greatly appreciated.