Chris E. answered 12/23/19
History and Writing Tutor with J.D. & M.A.
Mao led a communist revolution in China during the 1930s and into the 1940s culminating in the founding of modern China in 1949.
Mao led a communist revolt against the Nationalist Chinese government headed by Chiang Kai-shek. The Nationalists were more or less supported by Western powers including the United States. During this time, both the Communists and the Nationalists were fighting the Japanese. The Japanese had occupied large portions of China, including Manchuria, beginning in 1931, but the Japanese were expelled at the end of World War II in 1945. The defeated Nationalists fled to Taiwan at the conclusion of the Chinese Civil War in 1949.
Mao's success led to the creation of communist China. Chinese governments up to this point had earned a reputation as being corrupt, leadership was weak, and the country's status in the world was quite low. Mao promised to cure these ills, and enough people believed in his ideas and followed him. It is also worth noting that China had tried several different forms of government up this point, including democracy.
As you may know, the Cold War was mostly about the perceived threat of a world-wide communist revolution (see domino theory). After China turned communist, some in the U.S. government were asking, "Who lost China?"
Mao's China (1949-1976) formed an alliance with the Soviet government, Chinese troops battled the U.S. in the Korean War (1950-53), and eventually secured normalized relations with the U.S. following Nixon's trip to China (1972), a key moment in American foreign policy after WWII.
There's a lot more to the story, but those should be some good starting points for you!