The appendix

This is a good question. The party seeks to make history fluid. The party consistently retells and re-writes history to conform to ideology and the events that take place. The Declaration of Independence was a document meant to outlast time. It was a set of principles that should never alter. Thus we can see the irony of it being included in the appendix. A document like this would not be translatable in Newspeak. The inherent rights of the individual would have no connection in Newspeak or Orwell's world. Indeed, O'Brien would have simply called the whole document "crimethink".