On February 8, 1873, less than three weeks after leaving the governor's post, Geary was fatally stricken with a heart attack while preparing breakfast for his infant son in Harrisburg, Pennsylvania.
Den 8. februar 1873, mindre end tre uger efter at have forladt posten som guvernør, blev Gery ramt af et hjertetilfælde, mens han lavede morgenmad til sin lille søn i Harrisburg, Pennsylvania.