Wilderness! Just the idea means different things to different people, but there is a legal meaning.
The Wilderness Act was passed on September 3,1964, a time of true change for our country: the civil rights and environmental movements, Vietnam War, and the writing of Silent Spring by Rachel Carson. It was a time of transition from the industrial age to the idea that we can't keep developing our lands in an uncontrolled manner, extracting resources without thought of future impacts, and polluting our human environment (people, air, water, plants, soils, and animals) in a manner that results in a slow death.
"In order to assure that an increasing population, accompanied by expanding settlement and growing mechanization,
does not occupy and modify all areas within the United States and its possessions, leaving no lands designated for preservation and protection in their natural condition ... these wilderness areas shall be administered for the use and enjoyment of the American people in such manner as will leave them unimpaired for future use and enjoyment as wilderness, and so as to provide for the protection of these areas ..." P.L. 88-577 Sect. 2.a., 1964