What is the smallest national park in the United States?

Gateway Arch National Park is the smallest national park in the United States.

The park covers approximately 192.83 acres in St. Louis, Missouri, making it dramatically smaller than most American national parks. Its central landmark is the Gateway Arch, a 630-foot stainless-steel monument commemorating westward expansion and the Louisiana Purchase. The park also includes the Old Courthouse and a museum documenting the region’s history.

The site was originally created in 1935 as Jefferson National Expansion Memorial. Congress redesignated it as Gateway Arch National Park in 2018, giving it the official national park title. That change generated debate because the site is primarily urban, architectural and historical rather than a vast natural landscape.

A common mix-up is Hot Springs National Park, which is often described as the second-smallest U.S. national park. Biscayne and Congaree are much larger, despite their compact developed areas or limited visitor access. The answer refers to official National Park Service units designated as national parks.