I would think that understanding the word and the different ways it was used helps students understand history. This isn't really about how students today hear the word.... it's inappropriate nature is admonished immediately in today's world. None-the-less, the word is still in use. You have African Americans who use the word to denigrate each other, sometimes you might hear an elderly relative use the word without malice..... just because it was common when they were growing up. Historical documents cannot be changed without rewriting history..... and history needs to be known without falsification...... even the things our country is not proud of.