As an American, I will do my best to....
Be Clean in my outdoor manners
Be Careful with fire;
Be Considerate of the outdoors, and
Be Conservation-minded.
Center for Outdoor Ethics - LNT.org
Find out where you are going before you go. Are their rules you need to know? Activities you can or can't do? Drinking water available? Need to bring something special?
ALWAYS walk on Trails.
No shortcuts. Set up tents in marked areas.
Use bathroom facilities if available. Follow camp rules for handling dishwater. Pack out your trash unless camp has trash pickup.
"Leave nothing but footprints, take nothing but pictures, kill nothing but time."
Leave natural treasures where you found them so other campers can enjoy them too. Best souvenir is a picture.
Cook on a camp stove or grill when possible.
Only build fires in designated rings.
Always have someone watch until the fire is dead out.
Travel quietly and give animals space so you don't disturb them. This is their home, be considerate.
Getting too close to an animal can be dangerous for the animal and you.
Be respectful of other visitors by keeping noise down and don't enter other's campsites without permission. Be polite. Give them the respect you expect.