signed by FDR, and letters home from my uncle. He was killed in Italy 1944 and is buried there. I have no idea what will happen to these things when i pass on.

all over the country. Some specialize in certain aspects of the military while others are more general. So,e are good sized and others are smaller. You might want to start googling (or Duck Duck Go if you don't want to be tracked) military museums to find some that you might be willing to entrust this material to, perhaps even begin negotiations. When you find a really good match, you'll want to be sure your next of kin or executor is aware of your wishes.

Also, there are many collectors of military memorabilia - if you've ever watched Antiques Roadshow you've likely seen some appraised. If you can't connect with a museum, an appraiser specializing in military memorabilia might be able to put you in touch with a collector and give you an idea of its monetary value (of course it's real value is prisceless.) Apraisers can be pricey, but it might be worth the expense. Sorry to be rambling on but I hope it may help.