The Evolution of the Conservation Movement, 1850–1920

The Evolution of the Conservation Movement, 1850–1920 is an online exhibition from the Library of Congress' American Memory series. It documents the historical formation and cultural foundations of the movement to conserve and protect America's natural heritage, through books, pamphlets, government documents, manuscripts, prints, photographs, and motion picture footage drawn from the collections of the Library of Congress.

Source: Wikipedia — The Evolution of the Conservation Movement, 1850–1920 (CC BY-SA 4.0)