Usually, when a court finalized an adoption, the record is sealed and agencies are ordered not to disclose the original parent. In fact, in Kentucky, I had a client whose address changed in the middle of the adoption case several years earlier, and he never updated the court with his new address. He never found out what happened. The clerks were following correct procedure by not disclosing any information about the case to him without a judicial order. The idea is to protect confidences for all parties.
If you have any hope of getting these types of records unsealed, you will probably need a lawyer.
This is general informational response is based only on the information given. It should not be relied upon without consulting a lawyer and getting a full consultation. This response to the question does not create an attorney-client relationship.