Request communication by mail or phone. Place the forwarded letter in the envelope but do not seal the envelope. The related matters such as Birth Certificate copy are typically disposed off several years after the SSN's was issued. However, the Internal Revenue Service is adamant about not releasing copies of form 1040 tax returns to anyone other than the taxpayer or their legal representative with a court order. However, because no other national identification system was in place, it became convenient to use SSNs instead.
Most genealogists like to learn about their cousins and contemporaries.
All goals are valid, but those requiring contact with distant relatives have their pitfalls. If all fails with attempting to locate a distant relation, the SSA might be helpful in sending a beacon towards them, signaling that you are searching for them. The way to go about sending such a signal is the Letter Forwarding Service . The envelope should be unsealed and pre-stamped and should include your return address. A cover letter including all the facts you do have about the person with whom you wish to contact should accompany the unsealed envelope with your letter to the relation in it.