A. When the US Social Security system was established in 1935, as individual didn't need to show proof of birth to receive a Social Security number. In fact, the first SS-5 forms (used to apply for an SSN) weren't turned in to the Social Security Administration (SSA) <www.ssa.gov>, as they are now, but to an employer, a letter carrier or the post office. The newly formed SSA didn't have local offices, so it contracted with the US Postal Service to handle SS-5 forms.

Proof of birth didn't become an issue until an individual wanted to receive Social Security benefits. At that point, the person had to show he had indeed reached the age of 65 and was eligible to collect benefits. Although some of your relatives may have had birth certificates to submit, the SSA also accepted other records for verification of age.