According to the Social Security Administration a Social Security Number is composed of three parts totally nine digits. The first three digits is called the area number, the second set of two digits is called the group number and the final set of four digits is the serial number.

The Area Number is assigned by the geographical region. Prior to 1972, cards were issued in local Social Security offices around the country and the Area Number represented the state in which the card was issued. This did not necessarily have to be the state where the applicant lived, since a person could apply for their card in any Social Security office. Since 1972, when the Social Security Administration began assigning Social Security Numbers and issuing cards centrally from Baltimore, the area number assigned has been based on the ZIP code in the mailing address provided on the application for the original Social Security card. The applicant's mailing address does not have to be the same as their place of residence. With that said, this number does not necessarily represent the state of residence of the applicant prior to 1972 or currently.

However, generally numbers were assigned beginning in the northeast and moving west. People whose cards were issued on the East Coast states have the lowest numbers and those on the West Coast have the highest numbers.

The next two digits of the number are a code used to track fraudulent numbers and the last four digits are randomly assigned.

Although railroad employees were issued Social Security numbers the same as others but from 1937-1963 they had numbers ranging from 700-728 as the first three digits. In 1964 their numbers began to reflect the same as other workers. Some railroad workers received Social Security benefits and some did not so it is wise to check the Social Security Death Index in any case.

The Social Security Death Index is created by the Social Security Administration. If you find an error such as incorrect dates or data you should contact the local Social Security office. Be prepared though because you will need to provide acceptable proof to have the error corrected.

Sources: Social Security Administration www.ssa.gov and www.rootsweb.com