In the 1988 afterword, Christopher Lofting explains why the changes were made:

"When it was decided to reissue the Doctor Dolittle books, we were faced with a challenging opportunity and decision. In some of the books there were certain incidents depicted that, in light of today's sensitivities, were considered by some to be disrespectful to ethnic minorities and, therefore, perhaps inappropriate for today's young reader. In these centenary editions, this issue is addressed. . .

. . .After much soul-searching the consensus was that changes should be made. The deciding factor was the strong belief that the author himself would have immediately approved of making the alterations. Hugh Lofting would have been appalled at the suggestion that any part of his work could give offense and would have been the first to have made the changes himself. In any case, the alterations are minor enough not to interfere with the style and spirit of the original."

The McKissacks say in the foreword to 2001:

"Lofting wrote at a time when women couldn’t vote, African Americans were denied their most basic human rights, children had few rights, and European colonization of Africa and Asia was at its peak. Unfortunately, the original text and illustrations reflect the prevailing attitudes of the time and contain material that is offensive and demeaning to people of color. Times change, however, and so do attitudes. By the 1970s, parents and teachers were reluctant to share the Doctor Dolittle series with children. Consequently, the series went out of print in the United States , even though international book sales continued to be high. . .

. . .the original book is also marred by racially insensitive language and artwork. While we are opposed to book banning and censorship, we are equally as committed to the idea that no book should undermine a child’s self-esteem. To make this book more suitable for twenty-first century readers, some changes were necessary...

Revising an author’s work without his permission is not a task we took lightly. We began by carefully researching Lofting’s life, works, and times,...From all that we gathered, we carefully made very minor revisions with respect to the author’s style, the spirit of his characters, and the underlying theme present throughout his work—that all life should be valued and respected. The extent of our changes was limited to the following: reworking a section regarding the African prince, Bumpo, to be consistent with the revisions made in The Story of Doctor Dolittle [the McKissacks published a revision of this book in 1997]; and deleting offensive words and phrases scattered throughout the text. Actually, fewer revisions were necessary in this book than in the first.

We feel Michael Hague’s strong and colorful illustrations that replaced Lofting’s stereotypical depictions of dark-skinned people and the removal of all racial pejoratives have now made this a perfect reintroduction of a beloved classic…"

I’ll discuss the illustrations in the four versions later.   Next: FIRST APPEARANCE OF PRINCE BUMPO