Hey Guys, Next year im competing in my school's national history day competition, the prize is a trip to DC which would be great.
Well, the theme for next years competition is turning points in history. My idea is to show how the longbow changed warfare, but im open to suggestions, i just really want to find a topic related to trad archery

Will that is awesome. I really wish you luck. Just remember the bow was the first tool to store energy that we know of.

Will, research the English longbow and how it affected warfare in Europe. Of course literally every society that ever existed used the bow in one form or other. The Mongul horn bows would also be a good choice to research.
You've chosen a good topic that has endless possibilities.
Good luck with the contest/project.

The US Army was training a group of soldiers to shoot longbows during WWII. I don't know if they ever used them in war  though. That might be interesting to research.