Yes, trad was very much a British phenomenon and had a major youth audience. The big names were Barber, Bilk and Ball. It also had a closely related cousin in the form of skiffle, an offshoot from the Barber band.
There was also music of this sort in the US, even if it wasn't called trad. The names that come to mind are Bob Scobey, Lu Watters and the Firehouse Five. And, of course, Ory was still playing, not to mention the revival of George Lewis (new set of teeth, etc.)
You'll recognize that, as a member of the opposite "modernist" camp, I viewed all this with a touch of hostility and ridicule, though I've long since grown out of that juvenile stance.