Quiz: Interesting fact about a former president's family tree

[Anzeigenhauptmeister]

Some months ago, there was an astonishing and therefore tricky question about a former U.S. president on the German version of "Who wants to be a millionaire?":

President X, born in the year Y, ...

A) ... founded IBM.
B) ... wrote "Born in the USA".
C) ... has living grandchildren.
D) ... erected Area 51.

The correct answer was, of course, C.

I'm asking you now:
Who is the earliest former president with a living grandchild?

PS: Is that fact common knowledge among the well-educated parts of the American society?

[𝕭𝖆𝖕𝖙𝖎𝖘𝖙𝖆 𝕸𝖎𝖓𝖔𝖑𝖆]

Not American but the president in question is John Tyler and his grandson is 92 years old.

[Unconditional Surrender Truman]

I'm pretty sure every American with even a passing interest in U.S. history knows this fact.

[Anzeigenhauptmeister]

Not American but the president in question is John Tyler and his grandson is 92 years old.

John Tyler lived from March 29, 1790, till January 18, 1862 († 71).
His 92-year-old grandson's name is Harrison Ruffin Tyler.
John Tyler also had another living grandson up until not so long ago: Harrison's brother Lyon Gardiner Tyler, Jr., who died on September 26 in Franklin, Tennessee, at the age of 95. (That's why the plural was used in the possible answers.)

[Anzeigenhauptmeister]

I'm pretty sure every American with even a passing interest in U.S. history knows this fact.

Really? Do you guys learn that at school?

What will be the correct answer to that question once Harrison Ruffin Tyler has passed away?

[Anzeigenhauptmeister]

What will be the correct answer to that question once Harrison Ruffin Tyler has passed away?

[Xeuma]

What will be the correct answer to that question once Harrison Ruffin Tyler has passed away?

Herbert Hoover, I think.

[Anzeigenhauptmeister]

What will be the correct answer to that question once Harrison Ruffin Tyler has passed away?

Herbert Hoover, I think.

He seems to have a living grandson: Andrew Hoover (* 1940).
His other five grandchildren have all died.

Here's an article about his grandson losing his home in Colorado due to a wildfire back in 2012.

Moreover, his great-grandson Douglas Brigham died in a helicopter crash at the age of 52 in 2012.

I will do further investigation to see if there's another former president with a living grandchild. Thanks to you the options have been narrowed down significantly. 👍🏻

[Kingpoleon]

What will be the correct answer to that question once Harrison Ruffin Tyler has passed away?

Theodore Roosevelt’s daughter, Alice, adopted her deceased daughter’s child. As such, Theodore Roosevelt has an adopted grand daughter who is only seventy one years old.

Grover Cleveland had three grand children born after 1943, too. I can’t find it they are still alive or not.

[Unconditional Surrender Truman]

I'm pretty sure every American with even a passing interest in U.S. history knows this fact.

Really? Do you guys learn that at school?

No, it's just the sort of trivia that history nerds love to bring up.

[Anzeigenhauptmeister]

Grover Cleveland had three grand children born after 1943, too. I can’t find it they are still alive or not.

Here is an article about George Cleveland from 2015.

According to it, he runs the Gibson Center for Senior Services in North Conway, New Hampshire.
On their official website, he is still listed as the Executive Director. Thus, I assume that he is still alive; otherwise they wouldn't introduce him in the list of the staff members.

The article reveals some further interesting facts about George Cleveland:

• He is now 68 years old.
• He is a Jeb Bush supporter.
• His grandmother, Frances Folsom Cleveland, was the youngest First Lady ever.
• He was close friends with Lyon Gardiner Tyler, Jr., who passed away some weeks ago.