Walter Williams, last Confederate soldier, died Dec 1959 at the age of
117.
Albert Woolson, last Union soldier, died Aug 1956 at the age of 109.
The last Civil War widow, Alberta Martin, died Monday at a nursing home in
Enterprise. She was 97.
Gertrude Janeway, last Union widow, died Jan 2003 at the age of 93
Various editions of the Guinness Book of Records state that it was John B. Salling, who died 16th March 1959, aged 113 and 1 day. The world record for the oldest ever person did not reach the age of 114 until 1979, and I doubt the accuracy or authenticity of the claim of Walter Williams abovementioned. I would be interested to know the source of that information about Williams (I have not heard about him before).
Futher grubbing aroung in the FAQ of soc.history.war.us-civil-war reveals this extract
1. Albert Woolson of Minnesota was the last authenticated survivor of the Civil War. Woolson served as a Union drummer boy and died in 1956.
2. Determining the last Confederate veteran is more difficult. The most recent and thorough study by William Marvel, published in "Blue and Gray" magazine in Feb. 1991, finds that the last authenicated veteran of the Confederate army was Pleasant Crump of the 10th Alabama, who died on 31 Dec 1951. Previous claims to be the last veteran of the Confederate army (and of the whole War) were made for Walter Washington Williams (died 19 Dec 1959) of Texas and for John Salling (died 19 mar 1959) of Virginia. However, Marvel concluded that their claims must be rejected, since (among other reasons) census records indicated that, in 1860, Williams was only 5 years old and Salling was just 2 years old.