What happened April 1975 AD

Gates and Allen officially established Microsoft on April 4, 1975, with Gates as the CEO. The original name of "Micro-Soft" (short for microcomputer software) was suggested by Allen.

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.

Denise Lynn Oliverson, 25, disappeared near the Utah–Colorado border in Grand Junction on April 6 while riding her bicycle to her parents' house; her bike and sandals were found under a viaduct near a railroad bridge.

Twenty-four OECD members sign an agreement to establish a $25 billion lending facility to provide assistance to industrial nations hurt by high oil prices.

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.

President Gerald Ford had given a televised speech on 23 April, declaring an end to the Vietnam War and all U.S. aid. Frequent Wind continued around the clock, as North Vietnamese tanks breached defenses on the outskirts of Saigon.

Having transferred power to Trần Văn Hương, he left for Taiwan on 25 April.

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.

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.

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.