In the 19th century, Kentucky's Mammoth Cave launched an entire, very competitive cave tourism industry in the area, In 1925, Floyd Collins was trapped in the cave system, which was the beginning of the end of the cave wars.
Research:

SYMHC Classics: Moms Mabley
33:10

Behind the Scenes Minis: Self-talk Hoax
19:57

The Pompey Stone Hoax
35:25