April 4: In the Hague Tribunal, Israel demands reparations worth $3 billion from Germany. - West Ice accidents: During a severe storm in the West Ice, east of Greenland, 78 seal hunters on 5 Norwegian seal hunting vessels perish without a trace.

April 7: The American Research Bureau reports that the I Love Lucy episode, "The Marriage License" was the first TV show in history to be seen in around 10,000,000 homes the evening the episode aired.

April 8: Youngstown Sheet & Tube Co. v. Sawyer: The U.S. Supreme Court limits the power of the President to seize private business, after President Harry S. Truman nationalizes all steel mills in the United States, just before the 1952 steel strike begins.

April 9: Hugo Ballivian's government is overthrown by the Bolivian National Revolution, which starts a period of agrarian reform, universal suffrage and the nationalization of tin mines.

April 11: Battle of Nanri Island: The Republic of China seizes the island from the Peoples' Republic of China.

April 15: The United States B-52 Stratofortress flies for the first time.

April 18: Bolivia National Revolution: A universal vote enables indigenous peoples and women to vote, nationalizes mines and enacts agrarian reform. - West Germany and Japan form diplomatic relations.

April 26: The United States Navy aircraft carrier USS Wasp collides with the destroyer USS Hobson while on sea exercises in the Atlantic Ocean, killing 175 men.

April 28: The Treaty of San Francisco goes into effect, formally ending the war between Japan and the Allies, and simultaneously ending the occupation of the four main Japanese islands.

April 29: Lever House officially opens at 390 Park Avenue in New York City, heralding a new age of commercial architecture in the United States. Designed by Gordon Bunshaft of Skidmore, Owings and Merrill, it is the first International Style skyscraper. (source: Wikipedia)