An adoptee's adoption records would contain any information related to the adoption, this could include medical and social history, the adoption decree, letters from lawyers, birth family, other important people with connection to an adoption. It may also include photographs and the original birth certificate.
Most states in the United States do not allow an adoptee acess to their adoption records. There are only a handful of states that have an open adoption record policy. Meaning that an adoptee can access their adoption record.