Eighty years ago, Japan launched more than 350 fighters, bombers, and torpedo planes against the U.S. naval base in Hawaii — a "date which will live in infamy," in the words of President Franklin Roosevelt. In fact, that Sunday morning is so seared into America's memory that the tumult of the weeks and months afterward is often overlooked. LIFE.com presents rare and unpublished photos from Hawaii and the mainland, chronicling a nation's answer to an unprecedented act of war. More unseen photos of Pearl Harbor.