Research Paper/Senior Project?

I need some advice on what to do my Senior project on? For my 11th grade research paper, I did it on "The United States still would have gotten involved into World War II without the Attack on Pearl Harbor" (Teacher chose it). So Im trying to prove that the United States would still have got in the war with the events of Pearl Harbor. And for my senior project/graduation project, I need to get an item or prop and explain it for like 10 mins (has to be related to Research paper). And Idk what to have as a item/prop. Any suggestions will be apperciated. Some people told me, WWII items (helmet, gun) while others said get like a battle strategy map.