(or "inverted commas," as you wish)
Why is there a variance in punctuation with quotation marks at the end of a sentence?
Some writers would put them outside the period, others inside the period.

Same goes with commas inside or out?
Example:
See his comments on "political expedience," in Chapter 10. See his comments on "political expedience", in Chapter 10.

Is this a geographic difference, depending which side of the pond you are on? The style of particular publications versus others? What?

I worked for German gentleman, who was publishing in America, and all his books put them inside the period or comma. This confused me as a copyeditor, as I was taught in college that they go outside, following the conventions of the Chicago Manual of Style and the Modern Language Association.
To further confuse where they belong we put ! and ? inside the quotation marks.
He hollered, "What a country!"
She wrote, "Where do these quotation marks belong?"

Insights anyone?
Thanks
Susan

Thank you, Donna those links tell me a lot more than I asked. I have grumbled over trying to find some of that information in books, as it is usually buried.
Best wishes your way as well.
Susan