There are many reason for tossing an old history book out and not keeping them. One being mistakes pop up in the old books that were not caught in the proof reading. Dates of name misspelled. Toss in countries changing names, more info found out about a person or place that were not in the older books, but important to know now. Newer ways to give out the info in the books come up. Better pictures to use, more history piling up (it don't stop you know), and new fun ways to try and making learning history more fun. So there comes a time when the old books have to go and new ones have to take their place.

But I have learn that the older books do a much better job of telling what they want you to know, even tho the newer ones might look better and sound better, but have so many mistakes in them.

Books from before 1900 were bound in a lead based solution for this reason they were removed from public libraries and schools.

Kyle Ward has written a fine book on the history of American textbooks, and how the info changes over time
"Not Written in Stone"

Well actually, Northern still has books from 1986 XD

wow......OxO well Port Huron used to have old books
but I think they threw theres away

History was always a useless subject to me. Don't get me wrong. I actually enjoy learning about the past it's just that I'd rather do that leisurely not in a learning environment. No one really uses the things taught in history in the real world.