One statistic you will find, there were a large number of Civil War vets that died shortly after returning home from the war, say a year or so. I believe some of this can be tied to the doctors over prescribing a common catch all medicine of the time. The medicine was called "Blue Mass" or "Calomel", it was nothing more than a good old shot of Mercury. I've read accounts of soldiers getting a bottle of Calomel and self medicating long and hard. Abraham Lincoln was known to take "Blue Mass" or "Blue Pill" the mercury based medicine while in office and just look at a picture of him in 1861 and compare it to a picture made of him in 1865 shortly before his death. I'm sure the war was taking its toll also, but the "Blue Pill" was surely speeding things along.