The South Korean government's structure is determined by the Constitution of the Republic of Korea. This document has been revised several times since its first promulgation in 1948 at independence. However, it has retained many broad characteristics and with the exception of the short-lived Second Republic of South Korea, the country has always had a presidential system with an independent chief executive.[51] The first direct election was also held in 1948. Although South Korea experienced a series of military dictatorships from the 1960s up until the 1980s, it has since developed into a successful liberal democracy. Today, the CIA World Factbook describes South Korea's democracy as a "fully functioning modern democracy