Leave No Trace is the name of an organization and the founding principle behind it. The Leave No Trace foundation is headquartered in Boulder Colorado and is a 501.c.3 non-profit organization. The foundations and concepts that Leave No Trace are based upon come from the the 1960s and 1970s when activities such as camping, backpacking and outdoor exploration became more popular, increasing land use issues such as pollution, damage to the environment and lack of courtesy to other explorers.
The Leave No Trace 7 Principles, which are based on respect, conservation and consideration of both the land and fellow users were created for use of the outdoors, for both the backcountry and front country.
Master classes are available for educators and trainer from the organization, which focuses on how to teach the principles for the backcountry and front country.
You can learn more about Leave No Trace Ethics and Principles here: https://lnt.org/