Diem defeats Bao Dai in rigged election and proclaims himself President of Republic of Vietnam.
The US Military Assistance Advisor Group (MAAG) assumes responsibility, from French, for training South Vietnamese forces.
Communist insurgent activity in South Vietnam begins. Guerrillas assassinate more than 400 South Vietnamese officials. Thirty-seven armed companies are organized along the Mekong Delta.
John F. Kennedy narrowly defeats Richard Nixon for the presidency
US Air Force begins using Agent Orange -- a defoliant that came in metal orange containers-to expose roads and trails used by Vietcong forces
Kennedy's death meant that the problem of how to proceed in Vietnam fell squarely into the lap of his vice president, Lyndon Johnson.
On August 2, three North Vietnamese PT boats allegedly fire torpedoes at the USS Maddox, a destroyer located in the international waters of the Tonkin Gulf, some thirty miles off the coast of North Vietnam. The attack comes after six months of covert US and South Vietnamese naval operations. A second, even more highly disputed attack, is alleged to have taken place on August 4.
Sustained American bombing raids of North Vietnam, dubbed Operation Rolling Thunder, begin in February. The nearly continuous air raids would go on for three years.
Veterans from World Wars I and II, along with veterans from the Korean war stage a protest rally in New York City. Discharge and separation papers are burned in protest of US involvement in Vietnam.
In a major ground war effort dubbed Operation Cedar Falls, about 16,000 US and 14,000 South Vietnamese troops set out to destroy Vietcong operations and supply sites near Saigon. A massive system of tunnels is discovered in an area called the Iron Triangle, an apparent headquarters for Vietcong personnel.
In an effort to destroy Communist supply routes and base camps in Cambodia, President Nixon gives the go-ahead to "Operation Breakfast." The covert bombing of Cambodia, conducted without the knowledge of Congress or the American public, will continue for fourteen months.
A legacy of deception, concerning US policy in Vietnam, on the part of the military and the executive branch is revealed as the New York Times publishes the Pentagon Papers. The Nixon administration, eager to stop leaks of what they consider sensitive information, appeals to the Supreme Court to halt the publication. The Court decides in favor the Times and allows continued publication
In an attempt to force North Vietnam to make concessions in the ongoing peace talks, the Nixon administration orders heavy bombing of supply dumps and petroleum storage sites in and around Hanoi and Haiphong. The administration makes it clear to the North Vietnamese that no section of Vietnam is off-limits to bombing raids.
A cease-fire agreement that, in the words of Richard Nixon, "brings peace with honor in Vietnam and Southeast Asia," is signed in Paris by Henry Kissinger and Le Duc Tho. The agreement is to go into effect on January 28.
South Vietnamese President Duong Van Minh delivers an unconditional surrender to the Communists in the early hours of April 30. North Vietnamese Colonel Bui Tin accepts the surrender and assures Minh that, "...Only the Americans have been beaten. If you are patriots, consider this a moment of joy." As the few remaining Americans evacuate Saigon, the last two US servicemen to die in Vietnam are killed when their helicopter crashes.