Thank you all for the great responses.
More information for folks to ponder:
I have about 20 pages of detailed history that describes what happened in a region over the last 10,000 years. This is backstory to the current state of affairs. It gives context to how towns/keeps became ruins, how places became haunted, what transpired to create places of magic, what the gods did to influence people, etc. Much of this would not be known by players but I really need to keep track of it so I can keep my stories straight. Much of it is really seed information for future gaming but not in the same sense as a plotline for an adventure path or dungeon crawl. I also have a timeline for the same period that puts it all in simple table.
None of the existing categories really seems to fit game history and backstory neatly. It could go under Mechanics. It's too much to fit into the "home" category. I like @Cornelius' suggestion of Time Periods but so much of the material refers to other events it would be cumbersome to split it up arbitrarily by century or some other measurement of time.
This is one of the few square pegs I have left for categorization. Hence my putting off dealing with it for over a year....
