It's quite a mix involved.

Looking beyond those on topics post-1997, we see that some of the books are books in which the narrative is based on and adapted from contemporary AP material (like the post-JFK assassination book). Although this is interesting, the best books in the bundle to me are the memoirs/recollection books, like Saigon Has Fallen: A Wartime Recollection and My Time with the Kings: A Reporter's Recollections of Martin, Coretta and The Civil Rights Movement which sounds like a real interesting read and a nice primary source if you ever need to write a post about either of those topics in this subreddit.

Beyond that, you've got some pop history (The Early Kennedy book, for example) and two biographies. It is worth mentioning that the Dwight D. Eisenhower biography was written in 1969, which makes it a bit outdated.

If you're expecting proper scholarship, I suggest that you head to your favorite University Press bookshop and pick up some titles. But if anything I've mentioned above appeals to you, I see why you can't pay a few bucks (donate it to charity!) and get a few nice e-books.