When Syngman Rhee's government was ousted by the student-led pro-democracy uprising of April Revolution, he was elected the prime minister of the Second Republic in 1960.

After the country adopted a parliamentary system in response to Rhee's abuse of presidential power, Chang became the head of government.

Chang Myon's government ended when Park Chung Hee led a successful military coup on May 16, 1961.

Appointed a teacher at Dongsung Commerce High School[i] on April 1, 1931, he took on the responsibility of teaching English and rhetorical subjects.

[n] He translated James Gibbons' The Faith of Our Fathers: A Plain Exposition and Vindication of the Church Founded by Our Lord Jesus Christ into Korean[o] on July 4, 1944.

Immediately after the outbreak of the Korean War, on June 25, 1950, he actively solicited urgent aide from the United States and the UN.

In November 1950, Chang was appointed the second Prime Minister of the First Republic of Korea, a position he at first refused, but after an earnest request from Syngman Rhee, he accepted and went on to serve from October 1951 until April 29, 1952.

As the foremost leader of the opposition in the late 1950s, Chang Myon, a devout Catholic, already had a good relationship with Roh Ki-nam, the Bishop of Seoul, from the early 1940s.

Police claimed that Chang Myon was working with assassins paid by North Korea to depose Rhee.

[3] By the late 1950s Chang Myon emerged as the major alternative to Rhee, and in 1960, when Rhee was overthrown by the April 19 Movement and a popular revolution, Chang Myon was elected the Prime Minister of the Second Republic of Korea and de facto chief executive.

On September 18, 1955, he was defeated by a narrow margin by Shin Ik-hee for the Democratic Party's candidacy in the presidential election.

During his vice presidency, Chang came into conflict with Lee Ki-poong, an influential Liberal Party member, who sent spies and placed him under surveillance.

In the Republic of Korea's vice-presidential election of March 15, 1960, Chang suffered defeat at the hands of Lee Ki-poong by such a suspiciously large margin that protesters took to the streets alleging fraud.

[4] A thousand residents gathered in front of the opposition Democratic Party building in the southern city of Masan to protest.

[4] This tragic incident served as a catalyst for the April 19 Movement and the popular revolution that overthrew the Rhee regime in May 1960.

In response to Rhee’s authoritarian methods, the Second Republic adopted a parliamentary system with President Yun Posun as mostly a figurehead; real power was held by Chang and his cabinet.

Hence, the administration led by Prime Minister Chang Myon faced volatile political and grievous socioeconomic difficulties.

[5] Moreover, his administration had successfully designed the first five-year economic development plan that would have proven beneficial for all Koreans.

[6] In 1961, the Chang Myon administration attempted to resume talks on a treaty of relations between Japan and the Republic of Korea and discussed eight of the proposed articles designed to normalize diplomatic ties.

The Park Chung Hee government would later negotiate the 1965 Treaty on Basic Relations Between Japan and the Republic of Korea.

Chang Myon's Second Republic of Korea was overthrown in the May 16 coup led by Major-General Park Chung Hee on May 16, 1961.

Chang was buried in the Hehwa Catholic Church burial site on the mountain Cheonbosan in Gyeonggi Province.

On October 27, 1999, he was posthumously honored by President Kim Dae-jung of the Republic of Korea, with the first class rank of the Order of Merit for National Foundation.

[7] On the occasion of the hundredth birthday of Chang Myon, Cardinal Kim Sou-hwan celebrated a memorial mass at Hehwa Catholic Parish Church in August 1999.

He rhetorically asked: "How is it possible for the leaders of the May 16 military coup to declare that the Chang Myon administration of the Second Republic was already corrupt and incompetent in less than a month of its inception?

He lived in a small, unpretentious house (Seoul, Jongro-gu, Myongreun-dong, 1 Ga, 36-1) where he and his spouse spent most of their life and raised seven children.