King George Says 'No' To American Rebels, A Gunfight At OK Corral, Heart From A Baboon

1774 - The first Continental Congress adjourns in Philadelphia, Pennsylvania.

1775 - King George III goes before Parliament to declare the American colonies in rebellion, and authorized a military response to quell the American Revolution.

1861 - The Pony Express officially ceases operations.

1881 - The Gunfight at the O.K. Corral takes place at Tombstone, Arizona.

1936 - The first electric generator at Hoover Dam goes into full operation.

1977 - The last natural case of smallpox is discovered in Merca district, Somalia. The WHO and the CDC consider this date the anniversary of the eradication of smallpox, the most spectacular success of vaccination.

1984 - "Baby Fae" receives a heart transplant from a baboon.

2001 - The United States passes the USA PATRIOT Act into law.

2003 - The Cedar Fire, the second-largest fire in California history, kills 15 people, consumes 250,000 acres (1,000 km²), and destroys 2,200 homes around San Diego.