George Perkins Marsh (1801-1882) was the first to reveal the menace of environmental misuse, to explain its causes, and to prescribe reforms. David Lowenthal here offers fresh insights, from new sources, into Marsh's career and shows his relevance today. Marsh's devotion to the repair of nature, to the concerns of working people, to women's rights and to historical stewardship resonate more than ever. His Vermont birthplace is now a national park chronicling American conservation, and the crusade he launched is now global.