I generally enjoy these sorts of books—the sort of things Bill Bryson specializes in, where he choses some through-line that gives him a lens for presenting some particular view on a bunch of events through history.
And in fact Mark Kurlansky’s Cod is a great example of the genre.
To say that all of the things mentioned are a direct consequence of the great durability and fecundity of cod would be to take things too far—but its influence seems clear, and while there may not be causation, there certainly seems to be correlation.
So perhaps it’s not unreasonable to say that cod is the reason we live in the United States of America.