Under it's common name, the "Social Security Death Index" is an interesting beast. It is actually the Social Security Administration's Death Master File. It is one of the most used and frequently misunderstood databases available to genealogists. There are many reasons for the misunderstanding, including the unwillingness of some users to really even try and learn anything about that database.
Based upon my searches it appears that the Death Master File returns a zip code for the last residence. And therein lies the problem.
I searched for my grandmother, Ida Neill in the Social Security Death index at Ancestry.com FamilySearch, and Genealogybank.com All pulled up a last residence zipcode of 62321, which is the correct zip code for Grandma's last residence. However, 62321 is not the zip code only for Carthage, Illinois. Ancestry.com and FamilySearch indicate that 62321 only connects to Carthage. However, GenealogyBank correctly indicates that 62321 also connects to several other outlying towns as well as is shown in the images below.
Ancestry.com results screen for Ida Neill who died 21 July 1994; obtained on 10 December 2012. |
FamilySearch results screen for Ida Neill who died 21 July 1994; obtained on 10 December 2012. |
Genealogybank.com results screen for Ida Neill who died 21 July 1994; obtained on 10 December 2012. |
What About That Zip Code?
The "problem" is the zipcode 62321 is associated with several villages besides the City of Carthage. Genealogybank.com (shown above) shows the same list of villages that are shown in the search results screen from the USPS website's Look Up a Zip Code:
There is a problem.
Carthage is the Hancock County, Illinois, county seat and Bentley, Denver, Fountain Green, McCall and Webster are all outlying villages (collection of a few homes in a few cases) that at one point in time had their own post office, but no longer do.
Notice that Harmony was not included in that list.
There is a Harmony, Illinois, but it is in the northeastern part of the state. Hancock County is in the western part of the state--just about as west as Illinois gets. The Google map (if you zoom out) will show the relative positions.
View Carthage, IL 62321 in a larger map
So What Is the "Deal" With Harmony?
The Harmony that is the list of 62321 "towns" probably is a reference to Harmony Township--which there is in Hancock County, and is the township in which Bentley is located. At some point in time, the "township" got dropped and all that was left was "Harmony."