Jim: Thanks for your response. According to family folklore, Hiram was a soldier in the Civil War. The story goes that after the war was over (possibly referring to the surrender at Vicksburg) he started home on foot but died enroute of pneumonia in the summer of 1863. This would correspond with the info you've provided regarding his record of being "absent sick" on official muster rolls during his brief period of service with the 43rd.
Much obliged,
Lawrence