Forwards

Volume 10 of the series has two forwards. The first is included only in volumes 10-12 (Americans, American History, and American Presidents). Author Rhie Won-bok opens up the preface to the American volumes by saying that

Korea has complicated feelings about America. While it's true that one either glorifies the U.S. or opposes it, to look at it another way, the fact that it is so difficult to objectively discuss America demonstrates Korea's interest/care (관심) for the country.
우리는 미국에 대해 참으로 복잡한 감정을 가지고 있다. 그 특징은 찬미 (찬미) 아니면 반미라는 것으로, 미국을 비교적 객관적으로 바라보기 어렵다는 사실인데 거꾸로 얘기해서 그만큼 관심이 많다는 증거이기도 할 것이다

Rhie identifies the problem with Korea's perception of the U.S. as a lack of accurate information, which is

on the one hand, due to underlying racialism and xenophobia (or rejection of outside influence), and on the other hand due to insufficient experience with Europe and Asia, and also because we had a subjective experience with the U.S., the strongest nation, at a time when our country was backward.
한쪽은 민족주의를 바탕으로 한 와세배격 차원에서, 다른 한쪽은 유럽과 아시아를 충분히 겪지 못한 채 우리가 후진국일 때 세계 최강 미국을 주관적으로 경험했기 때문일 것이다.

He goes on to explain that the series was always intended to include the U.S., but that at the time that the original 9 volumes were done, he knew little about the U.S. (funny, that hasn't stopped many other writers) and, since so many others in Korea know so much about the U.S., he expected huge rebukes should he attempt a book. For these reasons, he put off writing the last three volumes for 20 years. Although he only spent a year and a half in the U.S. as an honorary professor, Rhie points out that during his 10 years living in Europe not a day went by when the U.S. was not in the news.
Finally Rhie explains why The U.S. should get three volumes. He goes out of his way to defend the importance of the seemingly superfluous volume on presidents
because the American president is

more than any other leader, the world's most powerful person, it is difficult to understand America properly without knowing about his appearance, style, and behaviors.
미국의 비중이 다른 나라보다 커서이기보다는 전세계 최고 권력자 할수 있는 미국 대통령들의 면모와 스타일, 제도를 알지 못하고는 미국을 제대로 알기 어렵기 때문니다.

I'm going to go ahead at this point and say I find his justification for adding the book about U.S. presidents a serious stretch of credibility. If I were a cynic, I just might say that Rhie, whose actual experience in America amounts to a year and a half, decided to pad out his series by writing a book about the presidents because that book would be really easy to research and write without a lot of first-hand knowledge. Also, the addition of America to the series in 2004 seems like a very mercenary attempt to capitalize on the vast market for these education-lite books. We'll see, maybe those two years really had a deep impression on him.
As for the second forward, which is an addition to the 2003 edition of the series, it mostly discusses the decision to colorize the illustrations and update the information in the books, but it contains one dynamite expression for any of you currently studying Korean as I am. When thanking those who helped him color the plates, he says 모두에게 고개 숙여 감사드립니다 ('To all of you, I bow my head in thanks'). Awesome.