My best recommendation, would to have a contest that could help you and your students.
Have a short essay contest for people who are intrested.
Just make it clear not to copy information, keep it simple(since you wanted a simple one), and put a notice on the bottom of the essay when you post the winner on your site that if the info is copied please contact you etc etc to protect yourself in any event.
This will promote students to know the history better if they are intrested.
Prize has tons of options (In fact telling that you will post it on the website in advance with the name of the student at the bottom with "written by xxxx xxyear" will make them happy I am sure). Motivation and enrichment is limitless.