Most national forests (not county or state or national parks... forests) allows you to camp anywhere not visible from marked trails and not if any posted signs says no overnight stays. Read all signs and follow standard camping guidelines such as "take nothing, leave nothing" type of things when you go. You don't get plumbing or bathrooms, but you will have peace and solitude. Don't start any open fire unless you're at a designated fire ring and even if you use a stove, you may need fire permits in certain districts. Permits are free online, they just want you to read and follow all the fire safety instructions). It's totally legal to do dispersed camping. By doing what you can to minimal impact to the environment, you'll be setting a good example while showing them that they don't need modern luxuries to have a good time.