I took it that the USA is a much larger market. He had a major record label and an procative manager, and the times were probably right for him as the leading light in a 'Movement'.

I liked his singing. It was his bloody harmonica playing I couldn't stand! But I'd like to think that his songs would have made it even it he hadn't as a performer. Look at the number of Bob Dylan songs recorded by other people that became major hits all around the world. In fact it was the easy way to have a hit for lots of people.