April 1 - The longrunning soap opera General Hospital debuts on ABC television in the United States.

April 3 - Southern Christian Leadership Conference volunteers kick off the Birmingham campaign (Birmingham, Alabama) against racial segregation in the United States with a sit-in.

April 7 - Yugoslavia is proclaimed to be a socialist republic, and Josip Broz Tito is named President for Life.

April 8 - The 35th Academy Awards ceremony is held. Lawrence of Arabia wins Best Picture.

April 9 - British statesman Sir Winston Churchill becomes an honorary citizen of the United States.

April 10 - The U.S. nuclear submarine Thresher sinks 220 mi (190 nmi; 350 km) east of Cape Cod; all 129 aboard (112 crewmen plus yard personnel) die.

April 12 - Martin Luther King, Jr., Ralph Abernathy, Fred Shuttlesworth and others are arrested in a Birmingham, Alabama protest for "parading without a permit". - The Soviet nuclear powered submarine K-33 collides with the Finnish merchant vessel M/S Finnclipper in the Danish Straits. Although severely damaged, both vessels make it to port.

April 14 - The Institute of Mental Health (Belgrade) is established.

April 15 - 70,000 marchers arrive in London from Aldermaston, to demonstrate against nuclear weapons.

April 16 - Martin Luther King, Jr. issues his Letter from Birmingham Jail.

April 20 - In Quebec, Canada, members of the terrorist group Front de libération du Québec, bomb a Canadian Army recruitment center, killing night watchman Wilfred V. O'Neill.

April 21-April 23 - The first election of the Supreme Institution of the Bahá'í Faith (known as the Universal House of Justice, whose seat is at the Bahá'í World Centre on Mount Carmel in Haifa, Israel) is held.

April 22 - Lester Bowles Pearson becomes the 14th Prime Minister of Canada.

April 28 - A general election is held in Italy.

April 29 - Buddy Rogers becomes the first WWWF Champion. (source: Wikipedia)