head of government in August 1960. The Second Republic saw the proliferation of political activity which had been repressed under the Rhee regime. Much of this activity was from leftist and student groups, which had been instrumental in the overthrow of the First Republic. Union membership and activity grew rapidly during the later months of 1960, including the Teachers' Union, Journalists' Union, and the Federation of Korean Trade Union. Around 2,000 demonstrations were held during the eight months of the Second Republic. Under pressure from the left, the Chang government carried out a series of purges of military and police officials who had been involved in anti-democratic activities or corruption. A Special Law to this effect was passed on 31 October 1960. 40,000 people were placed under investigation; of these, more than 2,200 government officials and 4,000 police officers were purged. In addition, the government considered reducing the size of the army by 100,000, although this plan was shelved. In economic terms as well, the government was faced with mounting instability. The government formulated a Five-Year Economic Development Plan, although it was unable to act on it prior to being overthrown. The Second Republic saw the hwan lose half of its value against the dollar between fall 1960 and spring 1961. Although the government had been established with support of the people, it had failed to implement effective reforms which brought about endless social unrest, political turmoil and ultimately, the May 16 coup. Military rule (1961–1963) The May 16 coup, led by Major General Park Chung-hee on 16 May 1961, put an effective end to the Second Republic. Park was one of a group of military leaders who had been pushing for the de-politicization of the military. Dissatisfied with the cleanup measures undertaken by the Second Republic and convinced that the current disoriented state would collapse into communism, they chose to take matters into their own hands. The National Assembly was dissolved and military officers replaced the civilian officials. In May 1961, the junta declared "Pledges of the Revolution": anticommunism; strengthened relations with the United States; an end to government corruption termed "fresh and clean morality"; a self-reliant economy; working towards reunification; and a return to democratic civilian government within two years. As a means to check the opposition, the military authority created the Korean Central Intelligence Agency (KCIA) in June 1961, with Kim Jong-pil, a relative of Park, as