I apologize if there's a better subreddit to ask this, but my grandfather has given me his Grandfather's Ledger because of my interest in history. I thought it was just a personal diary of sorts, but it has all kinds of interesting information about the goings-on in Celina, Texas in the 1920s. He has listed all the school age children in the county with their DOBs, weather information, payments to farmhands, deaths/births in the area, etc.
Long story short, I was planning on typing up the ledger over time, since it can be hard to read at times and many of his spellings are phonetic, but I wasn't sure if any libraries or organizations would be interested in the information, besides my family. Any other general tips on keeping the ledger in good shape would also be appreciated! I currently have it out of the sun and kept in a plastic bag when not being read.
I obviously understand if you want to keep it in the family, but I would urge you look into your local historical societies and see if they have interest in the ledger. A quick google search revealed that the Collin County Historical Society in McKinney already keeps the files of quite a few families in their archives, and I suspect they would be interested in your great grandfather's document if it is as extensive as you describe.
If any historian or student is looking for information on rural Texas of that era, they would be able to easily access the archives of the historical society and use the ledger to grab a snapshot of the time and place. The county society also might have existing materials from the time period that can be cross referenced with the ledger in order to increase its value and the information it provides. If kept alone and in your possession, the ledger is not able to be easily accessed for research.
Additionally, if your great grandfather or grandfather has a connection to an institution or university, then that would be another common location for materials to be archived for their later use as well.
There other archivists that probably have better tips on how to maintain the document, but I would make sure you throughly wash your hands before handling. It is best to avoid getting the oils from your hands on the materials. Some might recommend gloves as well. And pay special attention to caring for the spline (I assume it is a book?) as that is a common location for cracking and failure.
I'll echo /u/ombudsmen and say this would be something a local archives would be very interesting in acquiring. If you're going to approach an archives you could very well ask that it be digitized as a condition of donation, so you'd have a copy in the family. However, digitization costs time and money, so if you'd like to do that consider giving a monetary donation to accompany the book. You could also offer to donate your time, digitization labor is something that can be done by volunteers, it's easy to train people on that. If I were in your shoes I would probably donate the money as I don't have the time, but if you have the time, see what you and the archives can come up with.
If you'd like to keep this book, you'd be best served looking into getting a proper storage box for it, probably a scrapbook box from Hollinger Metal Edge company would fit the bill. A conventional plastic bag is not a good storage idea, it is off-gassing on the book which is bad for it, as well as trapping in whatever the book is off-gassing. (But if you donate it to an archives they'll take care of this sort of thing.)