I'm don't know a lot of poetry, but I remember enjoying Poe's "The Raven" when I was a junior in high school and we had to read it.
Once upon a midnight dreary, while I pondered weak and weary...
TIS
"Mankind must put an end to war before war puts an end to mankind. War will exist until that distant day when the conscientious objector enjoys the same reputation and prestige that the warrior does today." JFK