My Lai Massacre. Police respond violently to antiwar protests at Democratic National Convention in Chicago. Nixon elected president. Martin Luther King assassinated. Nixon orders first withdrawal of troops from Vietnam.
Fighting expands into Laos and Cambodia.
1970 Neutral Cambodian government overthrown and replaced with a pro-U.S. government. American troops cross border into Cambodia. Four students shot and killed by National Guard during antiwar protests at Kent State University. Congress repeals Gulf of Tonkin Resolution. 1971 South Vietnamese army, with support of the U.S. Air Force, attacks enemy strongholds in Laos.