Moth3r said:

He made a classic work "Henry the Green Engine" in 1951.

But, in 1972, the story was attacked by the national press for containing the phrase "as black as niggers". To solve the problem, he changed the offending sentence to "as black as soot", which has been used in all subsequent editions of the book.

1951?

That seems a little late in the day day to pass it off as just 'that's how folks talked back then.' Especially for a children's book.

I'm no expert, but I believe by the 50's polite society in the US was avoiding that term, at least in public and children's books.

Did that type of language, perhaps carry a different ammount of emotional weight in England?