Final answer:
The speech being referred to is known as the Day of Infamy Speech, delivered by President Franklin D. Roosevelt following the attack on Pearl Harbor, marking the United States' entry into World War II.
Step-by-step explanation:
The speech you are referring to is known as the Day of Infamy Speech. President Franklin D. Roosevelt delivered this address to Congress on December 8, 1941, the day after the Japanese attack on Pearl Harbor. In this speech, Roosevelt declared that December 7th would be a "date which will live in infamy", thereby requesting a declaration of war against Japan and emphasizing that the attack was a deliberate and secret one.
This marked the entry of the United States into World War II. While the "Four Freedoms" speech laid out a vision for the post-war world and the concept of the Arsenal of Democracy characterized the U.S. industrial support for the Allies during the war, it is the "Day of Infamy" that is associated with Roosevelt's response to Pearl Harbor.