The preservation of parks, wilderness, and wildlife has also aided liberty by keeping alive the 19th century sense of adventure and awe with which our forefathers greeted the American West. Many laws protecting environmental quality have promoted liberty by securing property against the destructive trespass of pollution. In our own time, the nearly universal appreciation of these preserved landscapes, restored waters, and cleaner air through outdoor recreation is a modern expression of our freedom and leisure to enjoy the wonderful life that generations past have built for us.