The USA has hosted the Olympics 8 times. Four Summer Olympics were held in the US:

  • St. Louis 1904
  • Los Angeles 1932
  • Los Angeles 1984
  • Atlanta 1996

And four Winter Olympics:

  • Lake Placid 1932
  • Squaw Valley 1960
  • Lake Placid 1980
  • Salt Lake City 2002

More than 200 nations participate each Olympics. It's considered to be the first sport event in the world. The 20-21st centuries' Olympics gave birth to such competitions as Youth Olympic Games and Paralympic Games. The Winter Olympics was also occurred in 1924, while Ancient Olympic Games took place in Ancient Greece from the 8th century BC to the 4th century AD.

More Info: en.wikipedia.org