The Portland city records were checked, and the following entry for Joseph Porter was found [Vol. 6, pg 17-18]:
Sadly, his burial plot in the Forest City Cemetery was "No. 22, S. Ground". This was the Strangers Ground*, where those without families or friends to claim them or purchase their plot were laid to rest. Though the strangers ground is marked on a map* of the cemetery, the actual plots inside this section are not, and the cemetery does not have records as to where this particular plot #22 would have been located.
JOSEPH PORTER was a sailor, and was from Yarmouth, Nova Scotia (the Descriptive Roll says New Brunswick), enlisting on behalf of the quota of the town of York, Maine. It is not known if he enlisted while in town, or may have signed up later in Portland when town agents needed to fill their quotas (there were several sailors from the area outside of York County who ended up in Company D). As the 27th ME was raised without there being a draft, the above news article erred in saying Mr Porter was a sub was a drafted man. He MAY have subbed for someone that was rejected from the company enlistment or, most likely, accepted a town bounty and just signed up. There were a few of this name in the Yarmouth area in the 1851 and 1861 Canada censuses, and it is not possible (at this time) to determine which one, if any, might be him.
An unknown soldier, in an unmarked grave.
*In later entries, the "Soldiers Lot" or "S. Lot", would at times be called the "Soldiers Ground" (or S. Ground), but the burials in this plot were numbered in order of their burials, so #22 would not have been used in 1862.
* The map of the cemetery was done during the WPA of the 1930's (they can be found here: WPA Maps), with the strangers ground being on the eastern side of the cemetery.
Sources for images:
Portland, ME Records of Deaths: Vol 6, pg 19 (on Family Search)
Portland Daily Press, 9 Oct 1862 (on Chronicling America)