What's the first National Park designated in the United States?

Yellowstone National Park is considered the first national park designated in the United States because it was established as such by an act signed into law by President Ulysses S. Grant on March 1, 1872. The designation of Yellowstone as a national park was significant as it marked a major milestone in the conservation movement worldwide, demonstrating a commitment to preserve and protect natural landscapes and wildlife for future generations. Yellowstone's unique features, including its geothermal activity, wildlife, and stunning natural beauty, made it an ideal choice for the first national park designation in the United States.