Lisa,
Several years ago, a Canadian book club from Toronto came to Oakland to meet with my book club to discuss the book: Nigger: The Strange Career of a Troublesome Word by Randall Kennedy. Most of them had origins in the Caribbean, a couple from England. In addition to their intelligent discourse about how ther "N" word plays out in Canada; it was ironic that one of the women told us a story about how she was put in a position to defend the word.

She was a former member of their cabinet/government, I forgot what they are called, sounds like what is equivalent to our congressperson. There was a town called Nigger Rock.

http://www.townshipsheritage.com/Eng/Archives/News/niggerrock.1.eng.html

This town is where a lot of slaves from the States escaped to freedom. Over the years, the blacks intermarried and mixed with the white population until eventually there was little or no trace of African blood. The now "white" townspeople wanted to change the name but the black historical society in that area was adamantaly opposed to it, citing what you said, about erasing history and erasing the African/black heritage. This woman from the book club was one of the people who went to bat for the historical society to maintain the name, so that the history would not be forgotten. Such an fascinating story.

There are places in Connecticut and other parts of New England where this "bleaching of the line" as Lalita Tademy says, has occurred, erasing the black legacy that was once there.