Mao Zedong became the communist leader of China in 1949.
Ray Bradbury is the famous science fiction writer who wrote the book 'Fahrenheit 451'.
Harry S. Truman became the president after Franklin Delano Roosevelt.
I do not understand the last question. 'In what year did the Korean War?' It does not look complete, but the Korean war began on June 25th, 1950 and ended on July 27th, 1953.