The following events occurred in April 1975: See more

• Neak Leung fell to Khmer Rouge insurgency, cutting off a critical supply line to the Cambodian capital of Phnom Penh. Cambodia's President See more

• Bobby Fischer refused to play in a chess match against Anatoly Karpov in Manila, turning down a chance to receive at least $1,500,000 and becoming the first world chess champion to voluntarily give up his title. At Amsterdam, the FIDE voted to award Karpov the … See more

• The Soviet manned space mission Soyuz 18a ended in failure during its ascent into orbit when a critical malfunction occurred when the third … See more

• The CN Tower was topped off at 1,185.4 feet or 553.33 meters in height, as the last section was put into place by a helicopter, making the building the largest free-standing structure … See more

• Bill Gates and Paul Allen incorporated Micro-Soft, Inc., in Albuquerque, New Mexico.
• The first military Operation Babylift flight, C5A 80218, crashed 27 minutes after takeoff, killing 144 of the 305 people on board, including 78 of the 243 children. Two cargo doors … See more

• Yen Chia-kan was sworn in as the new President of Nationalist China, as a 30-day period of official morning began for the late Chiang Kai-shek.
• With the conquest of South Vietnam See more