A solidly decent book which I think might come closer to 4 stars for the right reader, though I'm doubtful there are many people who align greatly as being the "right reader," so it's a bit of a conundrum.
So basically, the book covers the history of the vikings in North America in a very broad sense--from the Vinland of the sagas and the site at L'Anse aux Meadows to the Kensington Runestone and the 19th century surge of viking interest to the Thor movies and present-day white supremacist movements. It's an interesting topic and charts its course pretty well for the most part. However, it is written for an audience that basically has zero prior knowledge of anything viking-related, meaning that for anyone with some prior knowledge, there's going to be a fair amount of rehashing of facts already known. And I suspect that most people who might be interested in this book will already have some prior knowledge. Hence my thoughts that the "right reader" might be relatively rare. I may be mistaken, but I doubt that the first non-fiction book about vikings for anyone interested in the subject will be this one, and most books dealing with the subject cover some of the same subject matter. For anyone with some prior knowledge, this book doesn't really start until about page 50, at which point you're already a quarter of the way through.
That all said, it does provide a cohesive and easy to follow overview. I thought that the handling of the Scandinavian settlers in the Midwest and general 19th century fascination with vikings was pretty well done. Generally good bit-by-bit information in that section about supposed archaeological finds and the wishful thinking of the era. Same may be said of the sections dealing with a search for an American foundation myth and present-day nefarious forces. But the emphasis towards the end on comics and movies/tv shows threw me for a bit of a loop. They just felt tacked on, like the author was a fan of certain comics himself and really wanted to make sure they got a lot of attention but then felt like he needed to add a chapter on movies/tv series just so that he didn't get criticized for only focusing on comics, but that just opens up a whole can of worms in itself. If the book is going to have one chapter devoted to comics and one chapter devoted to film, then why isn't there another chapter devoted to fiction? The book's emphasis would imply that Tolkien wouldn't receive a great deal of attention (since wasn't American), but the guy did help launch the present day fantasy genre that thrives on both sides of the Atlantic with many books featuring blatant Norse themes. And that doesn't even touch on historic fiction. Nor does the book touch upon music and how viking imagery has so thoroughly infiltrated certain genres. So this portion of the book was, to me at least, very half-baked. Either fully tackle the topic of vikings in pop culture in North America, or very briefly touch on it. Trying to split the difference and arbitrarily focusing on comics and film was a poor decision.
Anyway, as I said at first, the book is solidly decent. It's a quick read, and if you actually know nothing about vikings, then you'll learn a lot, and if you know something about vikings, you'll likely discover some new tidbits of information mixed among the rehashing of things you already know. And before it's over, you'll also receive a deluge of information about Marvel's Thor and American Gods (the show, of course, not the book), whether you want it or not.