Here are a couple of reviews when it came out in 1970:
TIME magazine reviewed the book saying: "In the last decade or so, after almost a century of saloon art and horse operas that romanticized Indian fighters and white settlers, Americans have been developing a reasonably acute sense of the injustices and humiliations suffered by the Indians. But the details of how the West was won are not really part of the American consciousness ... Dee Brown, Western historian and head librarian at the University of Illinois, now attempts to balance the account. With the zeal of an IRS investigator, he audits US history's forgotten set of books. Compiled from old but rarely exploited sources plus a fresh look at dusty Government documents, Bury My Heart at Wounded Knee tallies the broken promises and treaties, the provocations, massacres, discriminatory policies and condescending diplomacy."[12] The Pulitzer-Prize winning Native American author N. Scott Momaday noted the book contains strong documentation of original sources, such as council records and firsthand descriptions. Stating that "it is, in fact, extraordinary on several accounts," he further compliments Brown's writing by saying that "the book is a story, whole narrative of singular integrity and precise continuity; that is what makes the book so hard to put aside, even when one has come to the end."[5] (from https://en.wikipedia.org/wiki/Bury_My_Heart_at_Wounded_Knee#Reception_of_the_book)
There is also an Emmy nominated HBO film that covers the last two chapters of the book. I plan on watching that soon. It is on Amazon Prime video.
Here is why James Mustich says we should read it:
James Mustich