December 7, 1941 was, in the words of President Franklin Delano Roosevelt, "a day which will live in infamy." On that date the Japanese Imperial Navy launched a surprise attack on the American military bases at Pearl Harbor, Hawaii. It was the first assault on American-held territory in a conflict that was already underway in Europe — a conflict that would soon become World War II, the most terrible war in history. America's entry into the war in the wake of the devastating Japanese attack was a dramatic turning point in the history of that conflict.