John Muir, a Scottish-American naturalist and writer, is often referred to as the father of modern conservation due to his tireless advocacy for the preservation of wilderness areas and his role in establishing national parks.

President Theodore Roosevelt signed the Antiquities Act of 1906, which empowered the president to establish national monuments by executive order, providing protection to significant natural and cultural sites.

The Sierra Club, founded in 1892 by John Muir and other conservationists, is one of the oldest and most influential environmental organizations in the United States, dedicated to protecting and preserving natural resources.

Yellowstone National Park, located in the western United States, was established in 1872 and is considered the first national park in the world.

Gifford Pinchot, a forester and conservationist, served as the first Chief Forester of the United States Forest Service from 1898 to 1910, shaping the agency's mission and policies.

Aldo Leopold's book 'A Sand County Almanac', published in 1949, is a collection of essays that explores the relationship between humans and the natural world, advocating for a land ethic and a more harmonious coexistence.

Rachel Carson, an American marine biologist and conservationist, is renowned for her book 'Silent Spring', published in 1962, which brought attention to the harmful effects of pesticides, especially DDT, on the environment and human health.

The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), signed in 1973, is an international agreement that aims to regulate the international trade of endangered species and their products.

Chico Mendes, a Brazilian rubber tapper and environmental activist, is renowned for his work in protecting the rainforests of the Amazon and raising awareness about the importance of sustainable development.

The World Wildlife Fund (WWF), founded in 1961, is an international non-governmental organization dedicated to the conservation of nature and the reduction of threats to the diversity of life on Earth.

Dian Fossey, an American primatologist and conservationist, is renowned for her work in studying and protecting the gorillas of the Virunga Mountains in central Africa.

The Exxon Valdez oil spill, which occurred in 1989, was a major environmental disaster involving the release of millions of gallons of crude oil into the Prince William Sound in Alaska, causing significant damage to the marine ecosystem.

Wangari Maathai, a Kenyan environmental and political activist, is renowned for her work in protecting the forests of Kenya, particularly through the Green Belt Movement, and promoting sustainable development.

The Kyoto Protocol, signed in 1992, was an international agreement that aimed to reduce greenhouse gas emissions and address climate change, setting targets for industrialized countries to reduce their emissions.

Jane Goodall, a British primatologist and anthropologist, is renowned for her work in studying and protecting chimpanzees in Tanzania, revolutionizing our understanding of primate behavior and their close relationship with humans.