Births on April 18

Pierre Pettigrew, Canadian businessman and politician, 5th Canadian Minister of Foreign Affairs

Pierre Stewart Pettigrew (born April 18, 1951) is a Canadian politician and businessperson.

11 Apr

President Truman's relief of General Douglas MacArthur
Korean War: President Harry Truman relieves General of the Army Douglas MacArthur of overall command in Korea.
22 Apr

Battle of Kapyong
Korean War: The Chinese People's Volunteer Army begin assaulting positions defended by the Royal Australian Regiment and the Princess Patricia's Canadian Light Infantry at the Battle of Kapyong.
25 Apr

Battle of Kapyong
Korean War: Assaulting Chinese forces are forced to withdraw after heavy fighting with UN forces, primarily made up of Australian and Canadian troops, at the Battle of Kapyong.
3 May

Harry Truman
The United States Senate Committee on Armed Services and United States Senate Committee on Foreign Relations begin their closed door hearings into the dismissal of General Douglas MacArthur by U.S. President Harry Truman.
15 Oct

Combined oral contraceptive pill
Mexican chemist Luis E. Miramontes conducts the very last step of the first synthesis of norethisterone, the progestin that would later be used in one of the first three oral contraceptives.