Which US national park, established in 1872, became the world's first national park?

Yellowstone National Park, established in 1872, became the world’s first national park.

President Ulysses S. Grant signed the Yellowstone National Park Protection Act on March 1, 1872. The law set aside land around the headwaters of the Yellowstone River as a public park for the benefit and enjoyment of the people. Yellowstone was located mainly in the Wyoming Territory, which had not yet become a state.

The park’s creation followed the Hayden Geological Survey of 1871, whose reports, photographs, and paintings publicized Yellowstone’s geysers, waterfalls, canyons, and other geothermal features. Congress chose federal protection rather than allowing the area to be sold or privately developed.

Yellowstone is often called the first national park in the world, although earlier protected royal hunting grounds and nature reserves existed elsewhere. It is also frequently confused with Yosemite, which became a national park in 1890. The National Park Service did not yet exist when Yellowstone was created; it was established in 1916, and the Army managed Yellowstone from 1886 until then.