> Founded more than 250 years ago

I wonder what the oldest company to go public is. This isn't easy to Google, because search engines want to give you the public company which is the oldest, even though that's not the same thing. I see this article about Birkenstocks, which company is apparently almost 250 years old. Surprising! But it does not mention Birkenstock being the oldest company at the time of IPO, so there must be an older one.

https://www.npr.org/2023/09/13/1198324691/birkenstock-ipo-st...