Fort Smith National Historic Site preserves the remains of two frontier-era military forts and the federal courthouse where Judge Isaac Parker dispensed frontier justice for 21 years. The site occupies the original fort grounds on a bluff above the confluence of the Arkansas and Poteau rivers, and the restored buildings — the old barracks converted into a courthouse, the basement jail known as "Hell on the Border," and the reconstructed gallows — give an unusually vivid picture of what law enforcement looked like in the 1870s–1890s.
The exhibits cover three interlocking stories: the military occupation of the frontier from 1817, the brutal passage of the Trail of Tears through this territory, and the era of Judge Parker's federal court. Parker's courtroom has been restored to its 1890s appearance, and the jail beneath it — designed to hold 70 prisoners, routinely packed with more than 200 — is sobering to walk through. The outdoor gallows is a full-scale reconstruction of the one used for executions; guides give frank talks about how it worked and why it was built on this scale.
Admission is charged; the site is operated by the National Park Service and is open daily except Thanksgiving, Christmas, and New Year's Day.