President John Tyler was born in 1790, and two of his grandsons are still alive: Lyon Gardiner Tyler, Jr., born in 1924, and Harrison Ruffin Tyler, born in 1928.
My father recently passed away at 88. His grandfather was a Civil War veteran.
His grandmother lived to be almost 104. I can just remember her a little bit. I was 5 when she died.
Not much to do with the question at hand but perhaps of some interest.
I didn’t even stop to think how rare this is but my grandfather is the grandchild of a Civil War veteran. I didn’t even know about it until this year when my grandfather mentioned it. His grandfather was William Henry James and was one of the last living Confederate Civil War veterans who died in 1949 at almost 101 years old. I have a Life magazine photo shoot with him and the other last of the last veterans in it. My grandfather is 86 and in good mental and physical health so he may be around for a while.
I did some research on this question a few minutes ago and there aren’t that many. Some were giving the estimate in the double digits but I don’t think they know about my grandfather. He has an older sister still alive as well. My grandfather was among the youngest of 12 from one of the last surviving veterans. It would take a lot to find any a lot younger than that.
Yeah, that is one of those freaky facts I like to keep in mind. I call it generation jumping when you can go back through a huge amount of time with just short links.
If they had reliably frozen his sperm before he died, the child could be any age, or might not even be born for another hundred years!
My mother was a grand-child of a Civil War veteran; she died in 1995.
When I was child there were several wives of Civil War vets living in my home town; the names and details are gone from my memory but I remember my Grandmother’s friends talking about a couple of them.
Four years ago I met a man who introduced himself as having a grandfather who fought in the civil war.
My brother-in-law, a physician, treated an elderly Spanish-American War vet for a while in the 70s. Unfortunately, the old fellow’s benefits were canceled when it was determined that he fought on the Spanish side. Tough break.
My paternal great-grandfather (born 1879) was the son of a Civil War veteran, and thanks to having two marriages and 18 children, a couple of his younger children from his second marriage are still around. I met one of his younger daughters, my great-aunt, a few years ago; she’s the granddaughter of a Civil War veteran.
As of a couple of years ago, my maternal grandmother still had a couple of siblings living, and they’re likewise all grandchildren of a Civil War veteran.
The Grand Army of the Republic and the United Confederate Veterans changed their names to the Sons of Union Veterans of the Civil War and the Sons of Confederate Veterans respectively once they started running out of actual veterans. The United Daughters of the Confederacy, so far as I know, contains no actual daughter of a Confederate veteran but the name is cool so they have kept it.
Douglas MacArthur’s son, Arthur MacArthur, who was named after his grandfather, who was also named Arthur MacArthur, a Civil War veteran, and is still alive and kicking. The grandson I mean. Not the Civil War veteran.
My grandfather was born in 1843, served in the Iowa infantry, attached to Sherman’s army. He was 70 in 1913 when my mother was born (youngest of his 22 children). I’m in my early 60s, so there must be a few others out there.
My aunt is 85. She is the grandchild of a Confederate veteran, and the great-grandchild of a War of 1812 veteran.
Holy cats! I think I’ve read this before on the Boards, but this still blows my tiny little mind. Wow.
Ward Cleaver’s grandfather fought in the War Between the States. (Episode, “Wally’s Pug Nose”)
Well, their dependents, anyway.
ETA:
I think it’s also been awhile since the Daughters of the American Revolution had any actual daughters of Revolutionary War vets. 
My grandfather was born in 1844, joined the Union 112th Infantry in 1862 ,mustered out in 1864 at Folly Island SC. My father was born in 1902 and I was born in 1949. Is that close enough?
Dan
No, Hoo is on First. Do you work for the Department and Defense?
The closest I can do is a surviving grandchild, under the age of 60, of a WW1 soldier. That would be my father (in his 50’s now), which makes me a great-grandchild of a WW1 soldier.
Sorry I can’t be of more help.
Seriously? My 25 year old brother-in-law is the grandchild of a WWI soldier.