Comments:

Simon Dallas was a soldier in the US Army.  At some time prior to his death Dallas would have been convicted by court marshal of some military offense and sentenced to the prison on Alcatraz, where he died.  The lack of a cross or other emblem on his tombstone reflects his inmate status.  Army inmates on Alcatraz were designated either as "military convicts" or "general prisoners."  Military convicts  had been dishonorably discharged and were spending the rest of their enlistment periods (or longer, if the offense was serious enough) in confinement. General prisoners like Dallas, however, were sentenced to Alcatraz for a period of time, but after that had been served they would be returned to their units and allowed to serve the rest of their enlistment.

Dallas has the oldest of the Alcatraz military prison graves from the Angel Island Cemetery.