What big event happened in 1968?

In the USA, with an emphasis on Vietnam.

January 12 - United States President Lyndon_Johnsonstates that the United States should stay in South_Vietnamuntil Communismaggression there is ended.

January 18 - About 8,000 U.S. soldiers land in South_Vietnam; U.S. troops now total 190,000.

March 29 - The 23rd Communist Party Conference is held in the Soviet_Union; Leonid_Brezhnevdemands that U.S. troops leave Vietnam, and announces that Chinese-Soviet relations are not satisfying.

April 29 - U.S. troops in Vietnamtotal 250,000.

June 29 - Vietnam_War: U.S. planes begin bombing Hanoiand Haiphong.

July 4 - President Lyndon_B._Johnsonsigns the Freedom_of_Information_Act_(United_States), which goes into effect the following year.

August 16 - Vietnam_War: The House_Un-American_Activities_Committeestarts investigating Americans who have aided the Viet_Cong, with the intent to make these activities illegal. Anti-war demonstrators disrupt the meeting and 50 are arrested.

For more, see: http://en.wikipedia.org/wiki/1966