Jim,
Between 1920 and 1939 the Open was won by Richard Burton, R.A. Whitcombe, Henry Cotton, Alfred Perry, Arthur Havers, Jock Hutchison, George Duncan making a total of 7 winners coming from Britain
With Denny Shute, Gene Sarazen, Robert Jones Jr. , Walter Hagen , James Barnes, Walter Hagen 6 winners came from the USA.
With Alfred Padgham I am not sure which nationality he had and Tommy Armour could be claimed by both GB and USA.
It is clear that especially the records of Walter Hagen and Bobby Jones are exceptional but it hardly constitutes the domination you talk about especially if you consider that the GB golfing scene had been decimated by the WWI.
While I agree that many great players in the post WWII era were from USA, to say that the likes of Gary Player, Peter Thomson, Bobby Locke and Henry Cotton did not make for a world class field is a statement that beggers belief. Snead also did not win everytime he played as you seem to believe and as I previously mentioned Hogan played in the Open because he felt he had to have won it atleast once in order to be considered a true golfing great.
Even after Palmers 2 wins 5 of the next 7 Opens were won by non USA players followed by a run of 12 out of 14 won by USA players, then 10 out of 11 by non USA. Seems to me the theory of American domination doesn’t stand up any more than that for non American. Conclusion seems to be that the worlds great golfers have always been spread through various continents and to me just because a few of them didn’t travel to play the Open doesn’t lessen the status of the competition, ask Walter Burkemo if the 1953 USPGA wasn’t a major because the dominant dead certain winner didn’t play!