George Perkins Marsh, an American scholar and diplomat, published Man and Nature: Or, Physical Geography as Modified by Human Action in 1864. This groundbreaking work argued that human activity profoundly shapes the Earth and warned of the dire consequences of failing to restore and sustain global resources. Recognized as one of the first books to document the environmental impacts of human actions, it was instrumental in launching the modern conservation movement and remains a seminal text in environmental thought.