The histories of the indigenous peoples of the Americas do not get the coverage they deserve. Author Reséndez presents the book discussing the enslavement of the Natives and that, rather than the introduction of European diseases was the cause that eventually killed the Indians (which is the term Reséndez uses).
The reader explores the history of Indian enslavement, traveling from the beginning in the Caribbean and traveling into the 20th century. How Indians made the "reverse Middle Passage" as he calls it from what would become the United States to Spain and other European countries. How the practice of enslavement began to take hold and maintained itself and simply changed as time marches on.
It's hard for me to review this book. It's an interesting premise and it seems he's done quite a bit of research but I'm absolutely not knowledgeable enough to say whether he's right or he's wrong or how to weigh the evidence. It's also difficult to assess because I think the book is a little too long: sometimes he's more interested in the history rather than focusing on the topic at hand. As other reviewers wrote sometimes the book feels episodic and it's not exactly about "the other slavery."
I do think it's absolutely a topic that should be explored more. It's part of dismantling the myth of those friendly Thanksgivings or that the Natives are part of a long dead culture that can only be seen in museums. Reséndez makes the very good point that when slavery is discussed in the US, it's more about black people, the Civil War, etc. The enslavement of American Indians was not certainly not something I learned about in school and I'd bet it's probably not unless you take particular classes at the college level or have a teacher at the grade school level who has it in the curriculum.
If it interests you I'd recommend you read it but I'd say try the library or see if you can get it as a bargain buy.