I do have the diary of a great-great (great?) uncle who wrote about his experiences as a soldier in the Civil War (Ohio Regiment, I think), at least until he got shot.

recall WWI

Don't know any stories of his, as he was gone much before I was born.

I do know that he was an Irish immigrant who was met at the dock with a Union uniform and told he had to fight or get back on the boat.

...in 1923, so I never knew him, as I was born in 1953. My dad was born in 1921, so did not know him either. I do have a picture of him in his later years, when he was living in a veteran's retirement home in Sandusky OH. Very, very long legs, which have shown up in our younger son, who is about 6'2". I'm 5'8". My husband is only 5'9", so the long legs certainly didn't come from his side of the family.

However, I have over a dozen letters written by him to his mother during his time in the army, and it is rather eerie to read his words about being encamped "about a mile from the rebs," and seeing names of generals that I've read about in history books. Also descriptions of taking prisoners and burying the dead.

war broke out.

I'm pretty sure he was dodging the draft instated by the CSA.

I was born in 1948. The youngest people born before 1865 would have been 83 at that time I was born. (My own grandmother was born in 1869.) There were a couple of elderly women in my neighborhood who had been slaves as children. Their earliest memories were mostly of the period just after the war.

The TV show "I've got a secret" in 1954 had a man who claimed to have witnessed Lincoln being shot. I remember seeing that show when first broadcast.

https://en.wikipedia.org/wiki/Albert_Woolson
According to Wikipedia, Albert Woolson was the last veteran of either side that his "status was undisputed". He died in 1956, so maybe someone on here will be able to tell you about this, but I can't. I was born after Mr. Woolson died. I hope someone has Civil War stories, I love first hand history accounts!