101 Objects that Made America is a collection by the Smithsonian. Have a look through the objects and see what you already know, or want to know, about American history. The categories are both predictable (“Inventions”) and unpredictable (“Happiness”).
Then, try to make your own list for Japanese history. Choosing only 101 objects will be difficult, as Japan’s history is much, much longer than that of the U.S., but give it a try! Or try to do it for another country you’re interested in researching.