Formerly Fort Phil Kearney: An American Saga. The Fetterman Massacre occurred on December 21, 1866, at Fort Phil Kearney, a small outpost in the foothills of the Big Horns. This story  has been written in many times in fiction and articles but this book is meticulously documented based on Army records and firsthand reports. This is the best account yet about the stirring events that took place.