On this day in history - September 20

What Happened On This Day – September 20

• 2011 The official US military policy of "don't ask, don't tell" ends

  The policy was instituted by the administration of Bill Clinton in 1994. Under the policy, openly gay personnel were not allowed to serve in the United States military, but they could serve as long as they did not reveal their LGBT status.

• 2001 American President, George W. Bush Declares War on Terror

  The global military campaign against terrorism was first declared in the aftermath of the September 11 attacks in the United States. The phrase was used by President Bush in a speech given to the United States Congress.

• 1984 The Cosby Show Airs for the First Time

  The popular television sitcom followed the lives of a Brooklyn-based African-American family called the Huxtables. The show ran for 8 years on NBC and was largely based on the stand up comedy of Bill Cosby, who played the role of Heathcliff "Cliff" Huxtable, the father in the show.

• 1973 Billie Jean King Wins the Battle of the Sexes

  The mixed gender tennis match between top tennis player Bobby Riggs and Billie Jean King was held in Houston, Texas after Riggs won another mixed gender match against Margaret Court earlier in the year. The matches were prompted by Riggs’ comments that even at an age of 55, he could beat any female tennis player. King beat Riggs and took home the $100,000 prize money. The match was and still is one of the most viewed tennis matches on television - it was watched by about 90 million people around the world.

• 1904 Wilbur Wright Makes the First Circular Flight

  Wright, who with his brother Orville, is credited for inventing the first airplane, made a complete circle in 1 minute and 16 seconds on the Wright Flyer II.