Mammoth Cave's TB Huts — The 1842 Underground Hospital
In 1842 a doctor moved sixteen tuberculosis patients into the world's longest cave to breathe its constant air — five died underground in the stone huts that National Park Service rangers now point out on tours, beside the graves of the experiment's victims.
Case File No. 254
FILE 01 The Legend
Dr. John Croghan bought Mammoth Cave in 1839, taken with reports that timber, dead bats and even desiccated prehistoric bodies never decayed in its passages — surely the cave air would heal consumption. In the winter of 1842 he settled sixteen tuberculosis patients in two stone and eight wooden huts along Broadway, the historic main passage. The experiment collapsed within months: smoke from lard-oil lanterns and heating fires, damp and darkness ravaged lungs; tourists on the public trails sometimes met gaunt patients in nightgowns shuffling past or heard coughing echo in the dark. Five patients died — their bodies laid out on what guides now call corpse rock — and Croghan returned the survivors to the surface in 1843. He died of tuberculosis himself in 1849.
FILE 02 The Sightings Log
The two stone huts still stand on the Broadway route, shown on NPS tours, and the Old Guide's Cemetery near the entrance holds three of the experiment's dead alongside Stephen Bishop, the enslaved explorer-guide who mapped the cave and called it “a grand, gloomy and peculiar place.” Cave guides' storytelling keeps the consumptive cough in the dark passages a standard bit of Mammoth lore; rangers report visitors asking about the huts' hauntings more than any other feature.
FILE 03 The Skeptic’s File
The National Park Service interprets the site as medical and African-American history, not haunting: the experiment is documented in detail — patient letters, the server Alfred's account of calling skeletons to dinner — and the geology explains the preservation that misled Croghan. The “ghosts” are a tour-narrative layer over one of the best-documented medical disasters in American caving.