About 2 million people from mainland China fled to Taiwan, joining about 6 million people who had earlier migrated to the island, mainly from the Fujian (Fukien) province across the Taiwan Strait.
Chiang Kai-shek, who was elected president of China under the constitution in 1947 and who had stepped down in 1949, resumed his presidency in 1950. He was reelected president four more times and died in 1975. Chiang ruled Taiwan in an authoritarian manner and invoked martial law because of the threat of invasion from the communist-ruled People’s Republic of China (PRC).
With the failure of the George Marshall mission to mediate the Chinese civil war, the United States became a bystander in the Chinese conflict until the invasion of Communist North Korea (later aided by "volunteers" from the PRC) of pro-Western South Korea in 1950.
The U.S. Seventh Fleet then began to patrol the Taiwan Strait to prevent a PRC invasion of Taiwan, and in 1952 the United States and the ROC signed a Mutual Defense Treaty (ended in 1979), which provided protection for Taiwan.
By 1954 Chiang’s government had completed a successful equitable land reform that transferred ownership to cultivators. Resource-poor Taiwan relied on social and educational reforms to produce a literate citizenry. U.S. economic aid helped to reform all aspects of the economy so that an even greater rate of growth became possible when it ended in 1964.
Industrial development began with labor-intensive light industries that capitalized on a literate workforce. Infrastructure building allowed the economy to shift to heavy, and later high technology, industries.
In 1978 the National Assembly elected Chiang Ching-kuo (son of Chiang Kai-shek) president; he was reelected in 1984 and died in 1989. Chiang Ching-kuo accelerated the rapid economic development of Taiwan, called an economic miracle by the rest of the world. He began political reforms that ended martial law, granted freedom of the press, and allowed opposition political parties.
The Chiang "dynasty" ended with Chiang Ching-kuo’s death (he had disavowed succession by his family members), and he was followed by his vice president, Lee Teng-hui. Lee continued democratization and won two more terms, the second by a universal suffrage vote (rather than election by the National Assembly) under an amended constitution.
In the 2000 election, the opposition Democratic Progressive Party candidate won the presidency. Taiwan thus added to its accomplishments the "political miracle" of a peaceful transformation from one-party rule to multiparty democracy without violence.
With a population of 23 million, it continued to be one of the most advanced and prosperous nations in Asia. However, Taiwan’s political future remained unclear because of the PRC’s stated goal of national unification, by force if necessary.