Which U.S. president signed the law establishing Yellowstone as the world’s first national park?

Ulysses S. Grant signed the law establishing Yellowstone as the world’s first national park.

Congress passed the Yellowstone National Park Protection Act, and President Grant signed it on March 1, 1872. The law set aside the Yellowstone region as a public park for the benefit and enjoyment of the people. The park lies mainly in Wyoming, with smaller sections in Montana and Idaho.

The decision followed exploration and scientific documentation, especially the Hayden Geological Survey of 1871. Photographs by William Henry Jackson and paintings by Thomas Moran helped persuade lawmakers that Yellowstone’s geysers, canyons, lakes, and wildlife should be protected rather than sold or developed privately.

Yellowstone was not the first protected landscape in any sense, and Indigenous peoples had long used the region. The national-park designation created a new model of large-scale public conservation that other countries later adopted. Theodore Roosevelt greatly expanded the U.S. conservation system decades afterward, but Grant signed Yellowstone’s founding law.