Day the Entire Mighty 8th Air Force Entered the Battle of the Bulge provides an account of the history and results of the largest aerial bombing mission ever. The story begins with Hitler's surprise last ground offensive, the Ardennes Offensive, and then details the Allies' response: the dramatic immobilization of air bases, rail yards, stock, and the destruction of bridges and supply facilities. The Germans were forced back to the east side of the Rhine River in what would be their final retreat in a war that would end with Hitler's suicide and Germany's surrender just a few months later.

Author Donald F. Kilburg, Jr., has a direct connection to the event through his father, who was the lead bombardier and received the Distinguished Flying Cross for his action that day. Kilburg, Jr., himself sits on the board of the 487th Bomb Group Association, whose members composed the lead formation of the 2046 heavy bombers dispatched that Christmas Eve in 1944. These participants encouraged him to write this book. Until Hitler's Last Christmas, the story of their most memorable mission had never been told in print.