> "Celebrating Ohio's and America's 250th birthday"

> Ohio is 223 years old

You might have misread the text? I see something different in the “Celebrating Ohio and America’s 250th birthday”, which I read as celebrating:

1. Ohio overall 2. America’s 250th

Without the Oxford comma, it was the most reasonable way to read it.

You would never put an Oxford comma in a list of two items

Exactly. If someone says, “I’m running to the grocery and McDonald’s drive-thru,” no one assumes they are sharing a drive-thru…

Pedantic HNers might...

For real there is no single collection of online pedantry more pedantic than HN.

	▲	embedding-shape an hour ago \| parent [-]
		Actually, before HN there was Usenet which I assure you, as I know everything, was much more pedantic than HN ever was.