The largest Irish Traveller enclave in the United States is just outside North Augusta, South Carolina. (right on the Georgia/South Carolina state line) They do not have a good reputation in SC because they have
supposedly ripped a lot of people off doing odd jobs and other home-improvement work like roofing, paving, and the like. Here is an article I found online about them.
Inside the world of Irish Travelers
In the Charlotte, North Carolina area, there is a fairly large Roma population, but I've not ever heard anything negative about them. I know two of the families and they both own large companies that have very good reputations. I went to one of their weddings and it was quite the opposite of a Traveller wedding. While there was a lot of glitz and glam, it was not over the top tacky--it was more like who could compete for the fanciest designer wear and jewelery, not the poofiest light up wedding dress and skimpiest outfit. I think that both Saks and Neiman-Marcus probably were emptied out by the time this wedding were over.