My avid passion for genetic genealogical research and my infrequent success (<10X) and single failure inspired me to post on the topic of "Adoptee and/or Bio-parents’ " search for one, the other, or both to connect/reconnect in the event that some is or knows someone who has been interested in connecting with blood-kin.
There are a good number of private and public organizations that facilitate searches and/or advise or guide searchers. Some charge and some do not. Unfortunately, I don’t have a comprehensive list of them, that’s probably just as well for “liability” reasons if and when a search fails or results in somebody’s disappointment.
That said, I think I’m safe in posting this link:
U.S. Department of Health and Human Services - Child Welfare Information Gateway