Well, well, well.

The Catholic presence in America was negligible until 1830. Yet we have a half-dozen saints.

Brazil was majority-Catholic since 1700 or thereabouts....and it's only had its first saint canonized.

I ascribe it to geography. The nearer you are to Rome, the more likely you are to be canonized, and Brazil is further from Rome than the USA is, at least in practice (easier to go through the North Atlantic than the doldrums, even now.)