This one had (possibly still has) me stumped...so I'll ask if this gentleman has anything to do with the answer. If so, I believe I cracked it!
Frank Herbert’s novel DUNE! Ann Frank = FRANK Herbert Hoover = HERBERT Sand dune = DUNE novel (I hope!)
Teddy Roosevelt and the Roughriders is the answer. Well done! I thought that this one might require a bit of thought! But what do I know?