I don't know anything about smoked fish and I don't really think of that as BBQ, but they did an overall great job on this.
https://www.bbc.com/travel/article/20250702-a-journey-through-the-united-states-of-barbecue
https://www.bbc.com/travel/article/20250702-a-journey-through-the-united-states-of-barbecue