Kim passed away at age 88 Sunday after being hospitalized since Thursday with a fever, according to Seoul National University Hospital.
Kim, whose presidency from 1993 to 1998 ended more than three decades of military rule, was regarded as moderate opposition leader and democracy advocate, and he rose in politics through the National Assembly from the 1950s to the 1970s, until he was expelled and a military regime put him under house arrest.
When first elected in his mid-20s, Kim was then the youngest member of the legislative house in 1954.
"As an iconic figure of South Korea's pro-democracy movement, he fought against military dictators for decades and laid the foundation of a peaceful power transfer in a country that had been marked by military coups," the semi-official Yonhap news agency reported Sunday.
But in 1979, his anti-government activities and opposition to then-President Park Chung-hee resulted in Kim's expulsion from the legislative chamber. Riots and protests ensued, and all 66 opposition members of the assembly resigned.
Later, in the early 1980s, President Chun Doo-hwan put Kim under house arrest twice that lasted two years. Kim staged a 23-day hunger strike that helped his return to politics.
Kim lost his first run for the presidency in 1987, but he won in the 1992 elections.
"We have created a truly civilian government. I will try to reunify the divided nation and open a new era for our people," Kim said in a victory statement that was reported in the Washington Post.
Kim sought to reform the government and target political corruption.
He had Chun and another military ex-president indicted on mutiny, treason and corruption charges stemming from a coup, and they were convicted and sent to prison. But two years later, Kim later pardoned Chun and Roh Tae-woo.
Chun and Roh, then army generals, had seized power in a 1979 coup.
For most of his administration, Kim enjoyed a rapidly growing economy.
He also faced what the semiofficial news agency called South Korea "first nuclear crisis in 1994 when the Clinton administration was considering striking Yongbyon -- home to North Korea's nuclear complex -- north of North Korea's capital, Pyongyang.
"Kim was vehemently against the idea, citing a possible war," the agency said.
The crisis was eventually defused.
Limited by the Constitution to a five-year term, Kim's administration experienced its own round of corruption in his last year. Even one of his sons, also a close aide, was arrested on charges of bribery and tax evasion, Yonhap reported.
Other Kim aides were implicated in a scandal over dubious loans to a failed steel company, putting several close associates in jail.
Kim apologized to the nation for the bribery scandal
and banished son Hyun-chul, then 37, from public life.
But that wasn't enough.
In October 1997, a South Korean court found son Kim Hyun-chul guilty of accepting bribes and evading taxes
and sentenced him to three years in prison. The son was ordered to pay a more than $1.5 million fine, and the court confiscated more than $500,000 in illegally amassed assets.
At the same time, the economy sank in Southeast Asia financial crisis.
"Kim was credited with disbanding a key military faction and bringing transparency to the nation's murky financial system. But he was accused of mismanaging the economy during the Asian financial crisis that toppled some of the country's debt-ridden conglomerates and forced the government to accept a US$58 billion bailout from the International Monetary Fund," Yonhap reported.
Kim was born into a well-to-do fishing family in the southeastern tip of the peninsula when the country was still under Japanese colonial rule. During the Korean War, he anchored a defense ministry's propaganda radio program, Yonhap reported.
Kim is survived by his wife, two sons and three daughters.