Nice job, just some minor grammar errors.

The most pronounced (This word doesn't quite fit here. Instead try using, "The worst problem was...") of all problems was famine.
All over the country, North Koreans died from lack of food.
Children tended to become street urchins, surviving through begging and stealing.
Experts believe that some 1.5~3 million died of famine during this period. Although the ‘Grueling March’ was the most serious of crises to threaten the North Korean regime as well as a period of unspeakable hardship for most of its people, it also served to solidify the one-man rule under Kim Jong-il.
​Meanwhile, Kim Dae-jung was elected to the presidency of South Korea in December 1997.