The conservation movement in the United States began in the 19th century, when there was a push to preserve natural wonders for future generations. Before Theodore Roosevelt became president of the United States, he advocated for the conservation of natural resources and founded the Boone and Crockett Club in 1887 specifically for this purpose. A few years later, John Muir and Robert Underwood Johnson established the Sierra Club in 1892 to advocate for the conservation of America's natural resources. Though the conservation movement tends to be thought of only in positive terms, native peoples had lived on these lands for millennia (and some areas like what would become Shenandoah National Park had long been settled) when the U.S. government took over the land to create the national parks that we enjoy today. Indeed, some of the tensions over federal lands still resonate.
The following resources provide government images on the subject of conservation.