Valera, Irish head of government from 1918 to 1932, loses power to an opposition coalition. John A. Costello is appointed Taoiseach by President Seán T. O'Kelly, until 1960. February 19 – The Conference of Youth and Students of Southeast Asia Fighting for Freedom and Independence convenes in Calcutta. February 21 – The United States stock car racing organization NASCAR is founded by Bill France, Sr. with other drivers. February 22 – The first of the Ben Yehuda Street bombings in Jerusalem kills between 49 and 58 civilians, and injures between 140 and 200. February 25 – 1948 Czechoslovak coup d'état: Edvard Beneš, President of Czechoslovakia, cedes control of the country to the Communist Party, a day celebrated by that regime as "Victorious February" (; ) until November 1989. February 28 Accra Riots: Riots take place in Accra, capital of the British colony of Gold Coast, when a peaceful protest march by ex-servicemen is broken up by police, leaving several members of the group dead, among them Sergeant Adjetey, one of the leaders. The 2nd Congress of the Communist Party of India convenes in Calcutta. March March 8 – McCollum v. Board of Education: The United States Supreme Court rules that religious instruction in public schools violates the U.S. Constitution. March 12 – The Costa Rican Civil War begins. March 17 The Treaty of Brussels is signed by Belgium, France, Luxembourg, the Netherlands and the United Kingdom, providing for economic, social and cultural collaboration and collective self-defence. The Hells Angels motorcycle gang is founded in California. March 18 – The Round Table Conference convenes in The Hague, Netherlands, to prepare the decolonization process for the Caribbean island of Aruba and the other Dutch Colonies. Aruba presents the mandate of the Aruban People for Aruba to become an independent country, under the sovereignty of the House of Orange, based on Aruba's first state constitution presented officially since August 1947, and a (4th) member state of the future Dutch Commonwealth. March 20 Singapore holds its first elections. Renowned Italian conductor Arturo Toscanini makes his television debut, conducting the NBC Symphony Orchestra in an all-Wagner program in the United States. The 20th Academy Awards Ceremony is held in Los Angeles. Gentleman's Agreement wins the Academy Award for Best Picture. April April – Children's Supermart, as predecessor of toys and children relative retailer brand Toys "R" Us, is founded in Washington D.C., United States. April