1774: The First Continental Congress adjourned in Philadelphia. 1854: C.W. Post, founder of Post Cereal Company, was born. 1861: The Pony Express made its last run on the day the first continental telegraph news dispatch was sent. 1936: The first generator at Boulder Dam (renamed Hoover Dam) began transmitting electricity to Los Angeles. 1940: The venerable P-51 Mustang took its maiden flight. 1951: Winston Churchill was elected to a second term as Prime Minister. 1954: Chevrolet unveiled its V-8 engine, at 265 cid. 1956: The International Atomic Energy Agency was established. 1966: Intelsat 2, the first Pacific communications satellite, was launched. 1972: Helicopter pioneer Igor Sikorsky died. 1977: The experimental space shuttle "Enterprise" glided to a bumpy but successful landing at Edwards Air Force Base in California. 1984: "Baby Fae" received a heart transplant from a baboon.