The Spencer Library Special Collections at the University of Kansas include one of the three or four largest SF collections in the country, including the papers of Theodore Sturgeon (so much material!), A. E. Van Vogt, James Gunn and a lot of other notables. Here’s info: https://spencer.lib.ku.edu/collections/special-collections/science-fiction
They also create free exhibits to present some of their collections, and from now ’til the end of July, they are presenting “Imagined Worlds: Writers and the Process of Speculative Fiction.” I’ve seen photos — it’s a lot bigger than the pic here — and it’s full of amazing things: letters, research and worldbuilding notes, awards, idea generation — even Theodore Sturgeon’s typewriter! I have three things in the exhibit: a Nebula and a World Fantasy Award, and one of my notebooks, with a paragraph in draft from the end of “Coyote Invents the Land of the Dead” and two unpublished beasts from “The Apartment Dweller’s Bestiary.”
Come for a visit, and we’ll go look at it together!