Oscar Will crops and their Native American origins.

Morning folks. I recently had Omaha pumpkin which I recently had from Sandhill in Iowa and grew some Winnebago or Ho-Chunk squash, Mandan sunflower and possibly Winnebago spotted corn to create a Siouan garden this year and came out wonderfully. Anybody know which tribes had the orchard and small black sweet corn years ago from the Will collection? Oscar Will was an interesting fellow known for collecting crops from many plain tribes and others, but don't know of his motive and whatnot. What's the origin of the Omaha pumpkin and any earlier history behind it? I'm trying to learn more of the indigenous identity of each of these crops to be better informed and present a better story to tell. Please shoot back if you all have anything to add. Take care!