
1954May 7, 1954
Vietnamese forces occupy the French command post at Dien Bien Phu and the French commander orders his troops to cease fire. The battle had lasted 55 days. Three thousand French troops were killed, 8,000 wounded. The Viet Minh suffered much worse, with 8,000 dead and 12,000 wounded, but the Vietnamese victory shattered France’s resolve to carry on the war.
1959
During 1959

A specialized North Vietnamese Army unit, Group 559, is formed to create a supply route from North Vietnam to Vietcong forces in South Vietnam. With the approval of Prince Sihanouk of Cambodia, Group 559 develops a primitive route along the Vietnamese/Cambodian border, with offshoots into Vietnam along its entire length. This eventually becomes known as the Ho Chi Minh Trail.

1961
Late 1961
President John F. Kennedy orders more help for the South Vietnamese government in its war against the Vietcong guerrillas. U.S. backing includes new equipment and more than 3,000 military advisors and support personnel.
December 11, 1961
American helicopters arrive at docks in South Vietnam along with 400 U.S. personnel, who will fly and maintain the aircraft.
1962
January 12, 1962

In Operation Chopper, helicopters flown by U.S. Army pilots ferry 1,000 South Vietnamese soldiers to sweep a NLF stronghold near Saigon. It marks America’s first combat missions against the Vietcong.
Early 1962
Operation Ranchhand begins. The goal of Ranchhand is to clear vegetation alongside highways, making it more difficult for the Vietcong to conceal themselves for ambushes. As the war continues, the scope of Ranchhand increases. Vast tracts of forest are sprayed with “Agent Orange,” an herbicide containing the deadly chemical Dioxin. Guerrilla trails and base areas are exposed, and crops that might feed Vietcong units are destroyed.
1963
January 2, 1963
At the hamlet of Ap Bac, the Vietcong 514th Battalion and local guerrilla forces ambush the South Vietnamese Army’s 7th division. For the first time, the Vietcong stand their ground against American machinery and South Vietnamese soldiers. Almost 400 South Vietnamese are killed or wounded. Three American advisors are slain.
1964
April – June 1964

American air power in Southeast Asia is massively reinforced. Two aircraft carriers arrive off the Vietnamese coast prompted by a North Vietnamese offensive in Laos.
July 30, 1964

On this night, South Vietnamese commandos attack two small North Vietnamese islands in the Gulf of Tonkin. The U.S. destroyer Maddox, an electronic spy ship, is 123 miles south with orders to electronically simulate an air attack to draw North Vietnamese boats away from the commandos.
August 4, 1964
The captain of the U.S.S. Maddox reports that his vessel has been fired on and that an attack is imminent. Though he later says that no attack took place, six hours after the initial report, a retaliation against North Vietnam is ordered by President Johnson. American jets bomb two naval bases, and destroy a major oil facility. Two U.S. planes are downed in the attack.
August 7, 1964
The U.S. congress passes the Gulf of Tonkin Resolution, giving President Johnson the power to take whatever actions he sees necessary to defend southeast Asia.

October 1964
China, North Vietnam’s neighbor and ally, successfully tests an atomic bomb.
November 1, 1964
Two days before the U.S. presidential election, Vietcong mortars shell Bien Hoa Air Base near Saigon. Four Americans are killed, 76 wounded. Five B-57 bombers are destroyed, and 15 are damaged.
1965
January 1 – February 7, 1965

Vietcong forces mount a series of attacks across South Vietnam. They briefly seize control of Binh Gia, a village only 40 miles from Saigon. Two hundred South Vietnamese troops are killed near Binh Gia, along with five American advisors.
February 7, 1965

A U.S. helicopter base and advisory compound in the central highlands of South Vietnam is attacked by NLF commandos. Nine Americans are killed and more than 70 are wounded. President Johnson immediately orders U.S. Navy fighter-bombers to attack military targets just inside North Vietnam.
February 10, 1965
A Vietcong-placed bomb explodes in a hotel in Qui Nonh, killing 23 American servicemen.
February 13, 1965
President Johnson authorizes Operation Rolling Thunder, a limited but long lasting bombing offensive. Its aim is to force North Vietnam to stop supporting Vietcong guerrillas in the South.
March 2, 1965
After a series of delays, the first bombing raids of Rolling Thunder are flown.
April 3, 1965
An American campaign against North Vietnam’s transport system begins. In a month-long offensive, Navy and Air Force planes hit bridges, road and rail junctions, truck parks and supply depots.
April 7, 1965
The U.S. offers North Vietnam economic aid in exchange for peace, but the offer is summarily rejected. Two weeks later, President Johnson raises America’s combat strength in Vietnam to more than 60,000 troops. Allied forces from Korea and Australia are added as a sign of international support.
May 11, 1965
Two and a half thousand Vietcong troops attack Song Be, a South Vietnamese provincial capital. After two days of fierce battles in and around the town, the Vietcong withdraw.
June 10, 1965
At Dong Xai, a South Vietnamese Army district headquarters and American Special Forces camp is overrun by a full Vietcong regiment. U.S. air attacks eventually drive the Vietcong away.
June 27, 1965
General William Westmoreland launches the first purely offensive operation by American ground forces in Vietnam, sweeping into NLF territory just northwest of Saigon.
August 17, 1965
After a deserter from the 1st Vietcong regiment reveals that an attack is imminent against the U.S. Marine base at Chu Lai, the American army launches Operation Starlite. In this, the first major battle of the Vietnam War, the United States scores a resounding victory. Ground forces, artillery from Chu Lai, ships and air support combine to kill nearly 700 Vietcong soldiers. U.S. forces sustain 45 dead and more than 200 wounded.
September – October 1965
After the North Vietnamese Army attacks a Special Forces camp at Plei Mei, the U.S. 1st Air Cavalry is deployed against enemy regiments that identified in the vicinity of the camp. The result is the battle of the Ia Drang. For 35 days, the division pursues and fights the 32d, 33d, and 66th North Vietnamese Regiments until the enemy, suffering heavy casualties, returns to bases in Cambodia.
November 17, 1965
Elements of the 66th North Vietnamese Regiment moving east toward Plei Mei encounter and ambush an American battalion. Neither reinforcements nor effective firepower can be brought in. When fighting ends that night, 60 percent of the Americans were casualties, and almost one of every three soldiers in the battalion had been killed.