China is, in one word, HUGE! How huge? The population is 4 times that of the US. Modern Day China was formed after the end of the Second World War. The Nationalist and Communists inthe country had an alliance against Japan in the war. After that, a civil war between the two ended in a Communist victory. Mao Zedong and his party gained control of mainland China and established the People’s Republic of China on October 1st, 1949.