What do the following U.S. presidents (and no others) have in common? George Washington John Adams Ulysses S. Grant Theodore Roosevelt Herbert Hoover Richard Nixon

Hoover and Nixon were Quakers, so that's something. Not the answer though.

I broke down and Googled. They all served as President at least partly when there were no living ex-presidents.

It's interesting that the last two presidents who share this property were both Quakers...

Indeed. This was inspired by seeing something on Twitter this morning about how the set of living ex-presidents ought to do something related to COVID-19.

I'm also a little impressed that you and @xgolferx figured it out. Thought maybe too hard. I'd planned a hint about how building the same list based on the list of British Monarchs since the Acts of Union 1707 en.wikipedia.org/wiki/List_o… would include all except for George VI.

It wasn't a trivial googling but some investigative journalism training back in college provided some good skills. The main approach I used was googling various collections of 4/6 of them until I hit on the answer. It's too obscure of a question for the obvious search to work.

I found a quiz site with @DuckDuckGo U.S. Presidents by Similarities Then focused my search on those questions that indicated (6) similarities Well played @wycats well played 🙌