This is a good look! J. Crew is the go to for classic American style with an array of cardigans, sweater vests, trenches, knit ties, and blazers. J. Crew can take you from The Grove to the weekend get away to South Hampton (or Gulf Shores, LOL!).
If you don't want to pay the J.Crew prices though, many retailers are selling vests like the one seen here. And you can find khakis and oxford shirts anywhere. Wear this, and remember, confidence looks good with anything. So power up the swagger.