The Jackdaw assignment typically involves a collection of artifacts that relate in some way to a book, story, or in this case, an episode in history. Assuming the instructor hasn't delineated a specific time period in history, one might consider the Lewis and Clark expedition as something that would be relatively easy to illustrate with objects. For example, a leather journal might be used to discuss the extensive records both men kept of the people, places, wildlife and vegetation that they discovered in their explorations. An extension of that idea would be to include items related to the animals and plants the men documented. Someone with a sense of humor might include a stuffed animal that represented one of the animals seen/killed/eaten on the journey; depending on which area of the country one is in, it might be possible to locate examples of leaves of plants documented by the explorers. Finally, it would not be difficult to locate online the enormous list of supplies that were taken as the journey began, and include some of those artifacts. For example, the supplies included needles for sewing clothing and blankets, easily found by today's consumer at virtually any crafts/fabric/home goods store.
Thanks so much, sounds like a fun project!