What happened 1975AD in Vietnam

On 10 March 1975, General Dung launched Campaign 275, a limited offensive into the Central Highlands, supported by tanks and heavy artillery. The target was Buôn Ma Thuột, in Đắk Lắk Province.

The ARVN proved incapable of resisting the onslaught, and its forces collapsed on 11 March.

On 20 March, Thieu reversed himself and ordered Huế, Vietnam's third-largest city, be held at all costs, and then changed his policy several times. As the North Vietnamese launched their attack, panic set in, and ARVN resistance withered.

On 22 March, the NVA opened the siege of Huế. Civilians flooded the airport and the docks hoping for any mode of escape.

By 28 March, 35,000 NVA troops were poised to attack the suburbs.

By 30 March 100,000 leaderless ARVN troops surrendered as the NVA marched victoriously through Da Nang. With the fall of the city, the defense of the Central Highlands and Northern provinces came to an end.

On 7 April, three North Vietnamese divisions attacked Xuân Lộc, 40 miles (64 km) east of Saigon. For two bloody weeks, severe fighting raged as the ARVN defenders made a last stand to try to block the North Vietnamese advance.

On 21 April, however, the exhausted garrison was ordered to withdraw towards Saigon. An embittered and tearful president Thieu resigned on the same day, declaring that the United States had betrayed South Vietnam. In a scathing attack, he suggested U.S. Secretary of State Henry Kissinger had tricked him into signing the Paris peace agreement two years earlier, promising military aid that failed to materialize.

On 27 April, 100,000 North Vietnamese troops encircled Saigon. The city was defended by about 30,000 ARVN troops. To hasten a collapse and foment panic, the NVA shelled the airport and forced its closure. With the air exit closed, large numbers of civilians found that they had no way out.

Schlesinger announced early in the morning of 29 April 1975 the evacuation from Saigon by helicopter of the last U.S. diplomatic, military, and civilian personnel. Frequent Wind was arguably the largest helicopter evacuation in history.

In the early morning hours of 30 April, the last U.S. Marines evacuated the embassy by helicopter, as civilians swamped the perimeter and poured into the grounds. Many of them had been employed by the Americans and were left to their fate.

On 30 April 1975, NVA troops entered the city of Saigon and quickly overcame all resistance, capturing key buildings and installations. A tank from the 324th Division crashed through the gates of the Independence Palace at 11:30 am local time and the Viet Cong flag was raised above it. President Dương Văn Minh, who had succeeded Huong two days earlier, surrendered to Colonel Bùi Tín.