I think what can be fairly said, is that while Blessed Fr.Seraphim may not be the first new world Saint (or new world convert Saint to be more specific), I think he has an affinity to we "moderns" that someone like St.Peter the Aleut may not. Fr.Seraphim was the product of basically the same culture as we are, and grappeled with many of the same "contemporary" problems we have. This is not to say any of these problems are unique to our culture or times... but I would say the combination of them, and to some extent their extremity, is.
Seraphim