The philosophy or policy that natural resources should be used cautiously and rationally so that they will remain available for future generations. Widespread and organized conservation movements, dedicated to preventing uncontrolled and irresponsible exploitation of forests, lands, wildlife, and water resources, first developed in the United States in the last decades of the nineteenth century. This was a time at which accelerating settlement and resource depletion made conservationist policies appealing both to aPage 305  |  Top of Article large portion of the public and to government leaders. Since then, international conservationist efforts, including work of the United Nations, have been responsible for monitoring natural resource use, setting up nature preserves, and controlling environmental destruction on both public and private lands around the world.

The name most often associated with the United States' early conservation movement is that of Gifford Pinchot, the first head of the U.S. Forest Service. A populist who fervently believed that the best use of nature was to improve the life of the common citizen, Pinchot brought scientific management methods to the Forest Service. He also brought a strongly utilitarian philosophy, which continues to prevail in the Forest Service. Beginning as an advisor to Theodore Roosevelt, himself an ardent conservationist, Pinchot had extensive influence in Washington and helped to steer conservation policies from the turn of the century to the 1940s. Pinchot had a number of important predecessors, however, in the development of American conservation. Among these was George Perkins Marsh, a Vermont forester and geographer whose 1864 publication, Man and Nature, is widely held as the wellspring of American environmental thought. Also influential was the work of John Wesley Powell, Clarence King, and other explorers and surveyors who, after the Civil War, set out across the continent to assess and catalog the country's physical and biological resources and their potential for development and settlement.

Conservation, as conceived by Pinchot, Powell, and Roosevelt was about using, not setting aside, natural resources. In their emphasis on wise resource use, these early conservationists were philosophically divided from the early preservationists, who argued that parts of the American wilderness should be preserved for their aesthetic value and for the survival of wildlife, not simply as a storehouse of useful commodities. Preservationists, led by the eloquent writer and champion of Yosemite Valley, John Muir, bitterly opposed the idea that the best vision for the nation's forests was that of an agricultural crop, developed to produce only useful species and products. Pinchot, however, insisted that "The object of [conservationist] forest policy is not to preserve the forests because they are beautiful...or because they are refuges for the wild creatures of the wilderness...but the making of prosperous homes...Every other consideration is secondary." Because of its more moderate and politically palatable stance, conservation became, by the turn of the century, the more popular position. By 1905 conservation had become a blanket term for nearly all defense of the environment; the earlier distinction was lost until it began to re-emerge in the 1960s as "environmentalists" began once again to object to conservation's anthropocentric (humancentered) emphasis. More recently deep ecologists and bioregionalists have likewise departed from mainstream conservation, arguing that other species have intrinsic rights to exist outside of human interests.

Several factors led conservationist ideas to develop and spread when they did. By the end of the nineteenth century European settlement had reached across the entire North American continent. The census of 1890 declared the American frontier closed, a blow to the American myth of the virgin continent. Even more important, loggers, miners, settlers, and livestock herders were laying waste to the nation's forests, grasslands, and mountains from New York to California. The accelerating, and often highly wasteful, commercial exploitation of natural resources went almost completely unchecked as political corruption and the economic power of timber and lumber barons made regulation impossible. At the same time, the disappearance of American wildlife was starkly obvious. Within a generation the legendary flocks of passenger pigeons disappeared entirely, many of them shot for pig feed while they roosted. Millions of bison were slaughtered by market hunters for their skins and tongues or by sportsmen shooting from passing trains. Natural landmarks were equally threatened—Niagara Falls nearly lost its water to hydropower development, and California's Sequoia groves and Yosemite Valley were threatened by logging and grazing.

At the same time, post-Civil War scientific surveys were crossing the continent, identifying wildlife and forest resources. As a consequence of this data gathering, evidence became available to document the depletion of the continent's resources, which had long been assumed inexhaustible. Travellers and writers, including John Muir, Theodore Roosevelt, and Gifford Pinchot, had the opportunity to witness the alarming destruction and to raise public awareness and concern. Meanwhile an increasing proportion of the population had come to live in cities. These urbanites worked in occupations not directly dependent upon resource exploitation, and they were sympathetic to the idea of preserving public lands for recreational interests. From the beginning this urban population provided much of the support for the conservation movement.

As a scientific, humanistic, and progressive policy, conservation has led to a great variety of projects. The development of a professionally trained forest service to maintain national forests has limited the uncontrolled "tree mining" practiced by logging and railroad companies of the nineteenth century. Conservation-minded presidents and administrators have set aside millions of acres public land for national forests, parks, and other uses for the benefit of the public. A corps of professionally trained game managers and wildlife managers has developed to maintain game birds, fish, and mammals for public recreation on federal lands. (For much of its history, federal game conservation has involved extensive predator elimination programs, howeverPage 306  |  Top of Article several decades of protest have led to more ecological approaches to game management in recent decades.) During the administration of Franklin D. Roosevelt, conservation projects included such economic development projects as the Tennessee Valley Authority (TVA), which dammed the Tennessee River for flood control and electricity generation. The Civilian Conservation Corps developed roads, built structures, and worked on erosion control projects for the public good. During this time the Soil Conservation Service was also set up to advise farmers in maintaining and developing their farmland.

At the same time, voluntary citizen conservation organizations have done extensive work to develop and maintain natural resources. The Izaak Walton League, Ducks Unlimited, and scores of local gun clubs and fishing groups have set up game sanctuaries, preserved wetlands, campaigned to control water pollution, and released young game birds and fish. Other organizations with less directly utilitarian objectives also worked in the name of conservation: the National Audubon Society, the Sierra Club, the Wilderness Society, The Nature Conservancy, and many other groups formed between 1895 and 1955 for the purpose of collective work and lobbying in defense of nature and wildlife.

An important aspect of conservation's growth has been the development of professional schools of forestry, game management, and wildlife management. When Gifford Pinchot began to study forestry, Yale had only meager resources and he gained the better part of his education at a French school of forest management in Nancy, France. Several decades later the Yale School of Forestry (financed largely by the wealthy Pinchot family) was able to produce such well-trained professionals as Aldo Leopold, who went on to develop the United States' first professional school of game management at the University of Wisconsin.

From the beginning, American conservation ideas, informed by the science of ecology and the practice of resource management on public lands, spread to other countries and regions. It is in recent decades, however, that the rhetoric of conservation has taken a prominent role in international development and affairs. The most visible international conservation organizations today is the United Nations Environment Program (UNEP), the Food and Agriculture Organization of the United Nations (FAO), and the World Wildlife Fund. In 1980 the International Union for the Conservation of Nature and Natural Resources (IUCN) published a document entitled the World Conservation Strategy, dedicated to helping individual states, and especially developing countries, plan for the maintenance and protection of soil, water, forests, and wildlife. A continuation and update of this theme appeared in 1987 with the publication of the UN World Commission on Environment and Development's paper, Our Common Future. The idea of sustainable development, a goal of ecologically balanced, conservation-oriented economic development, was introduced in this 1987 paper and has since become a dominant ideal in international development programs of the 1990s.