Nov. 26 (UPI) -- On this date in history: In 1789, U.S. President George Washington declared Nov. 26, 1789, to be Thanksgiving Day. It was the first U.S. holiday by presidential proclamation. Advertisement In 1922, in Egypt's Valley of the Kings, British archaeologists Howard Carter and George Carnarvon became the first humans to enter King Tutankhamen's treasure-laden tomb in more than 3,000 years. UPI File Photo In 1941, U.S. Secretary of State Cordell Hull submitted U.S. proposals to