Are those pieces made of ivory and does the set have a style/name ? Wasnt that the popular style before Staunton style chess pieces became so popular/famous ?
Madison

These are made of bone which is very similar to ivory in appearance. The style is barleycorn (or something very similar to barleycorn). I'm not such a chess set afficionado that I can distinguish differences that may differentiate similar styles.

Paragraph 2 "syle" [see - people do read these posts of yours :)]
Thanks... edited.

Barleycorn, not Regency. There is no "flowerpot" at the base...
I really like the ones with the standards or flags on the rooks.

Very nice. I missed this one the first time it made its rounds.
Here is a link to references to Chess by Thomas Jefferson and his family compiled by Monticello researchers:
https://www.monticello.org/site/research-and-collections/chess
Today is the birthday of James Madison, possibly my favorite US president. He was the impetus behind the framing of the constitution. Very likely the most avid chess player from among all the presidents, he often played marathon games with Thomas Jefferson, his friend and neighbor.
Here is Madison's chess set, also in my favorite style, a gift from Ben Frankin himself, discovered only four years ago and on display at Jefferson's estate, Monticello.