- Apr 1 Cambodia President Lon Nol flees for Red Khmer
- Apr 2 Vietnam War: Thousands of civilian refugees flee from the Quang Ngai Province in front of advancing North Vietnamese troops.
Sports History
Apr 3 Bobby Fischer stripped of world chess title for refusing to defend it, title awarded to Russian Anatoly Karpov
Founding of Microsoft
Apr 4 Microsoft is founded as a partnership between Bill Gates and Paul Allen to develop and sell BASIC interpreters for the Altair 8800
- Apr 4 British sitcom "The Good Life" starring Richard Briers, Felicity Kendal, Paul Eddington and Penelope Keith debuts on BBC One
- Apr 5 "Letter for Queen Victoria" closes at ANTA Theater NYC after 18 performances
- Apr 5 Soyuz 18A launch aborted short of orbit; cosmonauts return safely
- Apr 5 129th Grand National: Irish combination of jockey Tommy Carberry aboard L'Escargot wins by 15 lengths from 7/2 favourite and 1973-74 winner Red Rum
Sports History
Apr 5 American tennis #1 Chris Evert wins her 3rd WTA Tour Championship at the Los Angeles Sports Arena; beats Martina Navratilova 6-4, 6-2
- Apr 6 "Night... Made America Famous" closes at Barrymore NYC after 75 performances
- Apr 6 "The Rocky Horror Picture Show" closes at Belasco Theater NYC after 45 performances
- Apr 6 Bundy victim Denise Oliverson disappears from Grand Junction, Colorado
- Apr 6 Fastest hat trick by a Wash Cap 3 mins 26 secs (Stan Gilbertson)
- Apr 7 Preliminary meeting in Paris on world economic crisis between oil-exporting, oil-importing, and non-oil Third World countries
Academy Awards
Apr 8 47th Academy Awards: "The Godfather Part II", Ellen Burstyn & Art Carney win
Sports History
Apr 8 Frank Robinson debuts as 1st African American baseball manager (Cleveland Indians beat New York Yankees, 5-3)
Sports History
Apr 11 Hank Aaron returns to County Stadium as a Milwaukee player after his off-season trade from the Atlanta Braves; Brewers beat Cleveland Indians, 6-2
US Masters Golf
Apr 13 39th US Masters Tournament, Augusta National GC: Jack Nicklaus wins his 5th Masters title, 1 stroke ahead of Johnny Miller and Tom Weiskopf; Lee Elder, first African-American to compete in the tournament
- Apr 13 Chad military coup by General Odingar
- Apr 13 Christian Falange kills 27 Palestinians, begins Lebanese civil war
- Apr 15 1st appearance of San Diego Chicken
- Apr 15 Gabon amends constitution
- Apr 16 Cambodian Red Khmer occupy Phnom Penh
- Apr 17 The Khmer Rouge captures Phnom Penh, Cambodia marking the end of the Cambodian Civil war (Kampuchea National Day)
- Apr 19 India launches 1st satellite with help of USSR
- Apr 20 29th Tony Awards: Equus & Wiz win
Boston Marathon
Apr 21 79th Boston Marathon: American Bill Rodgers wins men's section in race record 2:09:55; Liane Winter of West Germany women's champion in 2:42:24 (female world record)
Historic Event
Apr 21 Last South Vietnam President Nguyen Van Thieu resigns after 10 years
Theater Premiere
Apr 23 Harold Pinter's play "No Man's Land" premieres in London
Election of Interest
Apr 25 Mário Soares' Socialist Party wins Portugal's first free election since 1925 following the Carnation Revolution of 1974
Baseball Record
Apr 26 Phillies Mike Schmidt's 2 HRs ties NL record of 11 HRs in April
- Apr 27 USSR performs nuclear test at Eastern Kazakh/Semipalitinsk USSR
TV Show Appearance
Apr 28 Ringo Starr appears on "The Smothers Brothers Show", singing Hoyt Axton's "No No Song", and John Lennon is the guest on Tom Snyder's "Tomorrow" program, in what turns out to be his final television interview
The Fall of Saigon
Apr 29 Vietnam War: US begins to evacuate its citizens from Saigon in Operation Frequent Wind in response to advancing North Vietnamese forces, bringing an end to US involvement in the war