A single word can have huge power and inspire years of debate. That’s how it was in naming a remote memorial on Colorado’s eastern plains "The Sand Creek Massacre National Historic Site."

The word “massacre” carries a lot of weight, as historian Ari Kelman writes in a new book. He documents the struggle to memorialize a killing field, where the U.S. Army murdered more than 150 Arapaho and Cheyenne Indians, mostly women, children, and the elderly in November, 1864.

Kelman’s book is called “A Misplaced Massacre: Struggling Over the Memory of Sand Creek.” (Misplaced because, for a long time, it wasn’t clear exactly where the killing had occurred.)