1626	Plymouth Colony passes ordinances regulating the cutting and sale of timber on colony lands.
1634	Plymouth prohibits the setting of forest fires.
1639	Newport, Rhode Island, prohibits deer hunting for six months.
1681	William Penn, proprietor of Pennsylvania, decrees that for every five acres of land cleared, one must be left forested.
1691	British colonial policy provides for reserving large trees, suitable for masts, in New England by marking them with a “broad arrow”.
1710	Massachusetts protects waterfowl in coastal regions.
1711	The White Pine Act of Parliament extends protection of trees suitable for masts.
1718	Massachusetts prohibits deer hunting for four years.
1739	Connecticut creates an annual closed season for deer.
1772	New York creates a closed season on quail and partridge.
1804-06	Meriwether Lewis and William Clark lead the first American transcontinental exploration.
1828-31	First experiment in federal forest management with live oaks on Santa Rosa Peninsula, Florida.
1832	George Catlin proposes a national park.
1849	US Department of the Interior established.
1858	Mount Vernon purchased as an historical site.
1864	Yosemite Valley, California, reserved as a state park.
1864	George Perkins Marsh publishes Men and Nature.
1869	John Welsey Powell descends the Colorado River through the Grand Canyon.
1871	US Fish Commission created.
1872	Arbor Day designated as April 10 as a result of the efforts of J Sterling Morton; currently celebrated last Friday in April.
1872	Yellowstone National Park established.
1875	American Forestry Association organised.
1876	Appalachian Mountain Club organised.
1878	John Wesley Powell publishes Report on the Lands of the Arid Region of the United States.
1879	US Geological Survey established.
1881	Division of Forestry created in the Department of Agriculture as a fact-finding agency.
1882	American Forestry Congress organised.
1885	New York, in co-operation with Ontario, creates the Niagara Reservation, protecting the Falls.
1885	New York establishes the Adirondack Forest Preserve (later Adirondack State Park).
1885	Predecessor of the US Biological Survey created in the Department of Agriculture as the Division of Economic Ornithology and Mammalogy.
1885	Boore and Crockett Club founded.
1886	New York Audubon Society organised.
1886	Bernhard E Fernow assumes direction of an expanded Division of Forestry.
1890	US Census announces the end of the frontier as a definable line.
1890	Yosemite National Park established.
1891	Forest Reserve Act permits the president to establish forest reserves (later national forests) on the public domain.
1891	National Irrigation Congress organised.
1892	Sierra Club founded.
1895	American Scenic and Historic Preservation Society founded.
1897	Forest Management Act defines purpose of the forest reserves.
1898	First college-level work in forestry offered at Cornell.
1898	Gifford Pinchot named head of the Division of Forestry.
1899	River and Harbor Act establishes the first legal basis for banning pollution of navigable waterways.
1900	Society of American Foresters founded.
1900	Lacey Act makes interstate shipment of game killed in violation of state laws a federal offense.
1902	Reclamation (Newlands) Act establishes Bureau of Reclamation in the Department of the Interior and launches a federal reclamation program.
1905	National Audubon Society formed.
1905	Forest reserves transferred from the Department of the Interior to the Forest Service within Department of Agriculture.
1906	Antiquities Act permits reservation of areas of scientific or historical interest on federal land as national monuments.
1907	Inland Waterways Commission established.
1908	Grand Canyon of the Colorado made a national monument.
1908	Theodore Roosevelt hosts a conference of governors at the White House on the subject of conservation.
1908	National Conservation Commission appointed to inventory resources.
1909	North American Conservation Conference held in Washington.
1909	National Conservation Association organised as a private group to replace the National Conservation Commission.
1910	The Forest Products Laboratory established by the Forest Service in Madison, Wisconsin.
1910	The Ballinger-Pinchot controversy disrupts the conservation movement.
1911	American Game Protective and Propagation Association founded.
1911	Weeks Act, permitting purchase of forested land at headwaters of navigable streams for inclusion in the national forest system, makes possible the establishment of national forests in the East.
1913	Hetch Hetchy Valley in Yosemite National Park granted to San Francisco for a reservoir after prolonged controversy.
1916	National Park Service Act.
1918	Migratory Bird Treaty Act implements 1916 treaty with Canada to restrict hunting of migratory species.
1918	Save-the-Redwoods-League founded.
1920	Federal Water Power Act gives the Federal Power Commission authority to issue licences for hydropower development.
1922	Izaak Walton League organized.
1924	Oil Pollution Control Act.
1924	Teapot Dome scandal.
1924	The Forest Service designates first extensive wilderness area in theGila National Forest, New Mexico.
1924	The first National Conference on Outdoor Recreation held in Washington DC.
1924	Clarke-McNary act extends federal ability to buy lands for inclusion in the National Forest system and provides for private state, and federal cooperation in forest management.
1926	Restoration of Williamsburg, Virginia, begun.
1928	Boulder Canyon Project (Hoover Dam) authorized.
1928	McSweeney-McNary Act authorizes a broad program of federal forestry research.
1933	Civilian Conservation Corps established.
1933	Tennessee Valley Authority created.
1933	Franklin D. Roosevelt creates the Soil Erosion Service as an emergency measure.
1934	Taylor Grazing Act provides for retention and federal regulation of use of unreserved public domain.
1935	Soil Conservation Act extends federal involvement in erosion control and establishes the Soil Conservation Service in the Department of Agriculture.
1936	National Wildlife Federation, with 4.6 million members by the 1980s, founded.
1936	Omnibus Flood Control Act establishes a national flood prevention policy under the US Army Corps of Engineers and the Department of Agriculture.
1937	Federal Aid in Wildlife Restoration (Pittman-Robertson) Act makes federal funds available to states for wildlife protection and propagation.
1939	Forest Service “U” regulations extend the policy of wilderness preservation in the national forests.
1940	The creation of the US Fish and Wildlife Service consolidates federal protection and propagation activities.
1944	Soil Conservation Society of America founded.
1946	US Bureau of Land Management established to consolidate the administration of the public domain.
1948	Federal Water Pollution Control Law enacted to regular waste disposal.
1948	Donora, Pennsylvania, experiences severe air pollution; twenty die and 14,000 become ill.
1949	The first Sierra Club Biennial Wilderness Conference held.
1949	Congress charters the National Trust for Historic Preservation.
1949	Aldo Leopold’s A Sand County Almanac published posthumously.
1952	London’s “Killer Smog” leaves 4,000 dead in a weekend and leads to effective air pollution regulations.
1956	Mission 66 launched as a ten-year improvement program for national parks.
1956	Echo Park Dam, scheduled for construction in Dinosaur National Monument, deleted from the Upper Colorado River Storage Project, marking a victory for wilderness preservation and the National Park system.
1956	Water Pollution Control Act provides federal grants for water treatment plants.
1958	Congress appoints the Outdoor Recreation Resources Review Commission to study and report on the nation’s future needs.
1960	The Multiple Use-Sustained Yield Act defines the purpose of the national forests to admit nonmaterial benefits.
1962	President John F Kennedy and Secretary of the Interior Stewart Udall host a White House Conference on Conservation.
1962	Rachel Carson publishes Silent Spring.
1963	Clean Air Act authorizes federal hearings and legal actions.
1963	The Bureau of Outdoor Recreation established within the Department of the interior to coordinate federal efforts.
1964	Wilderness Act establishes the National Wilderness Preservation System.
1964	Canyonlands National Park established.
1965	Land and Water Conservation Fund Act makes money available for local, state, and federal acquisition and development of park land and open space.
1965	Storm King (Scenic Hudson) case admits scenic and recreational criteria in legal actions.
1965	Lyndon B Johnson hosts a White House Conference on Natural Beauty.
1966	National Historic Preservation Act passed.
1966	Endangered Species Act begins federal involvement in habitat protection and rare species identification.
1967	Environmental Defense Fund established.
1968	Paul Elrich publishes The Population Bomb.
1968	National Wild and Scenic Rivers Act and National Trails System Act passed.
1968	Grand Canyon Dams defeated.
1968	First manned flight to circle the moon produces dramatic photographs of “spaceship earth.”