According to Wikipedia, the town was established in 1854, 27 years after the establishment of Ft. Leavenworth just to the North.
This was the same year (1854) the Kansas-Nebraska Act which allowed the citizens to decided whether to allow slavery in the two territories it established. Lecompton, KS (essentially pro-slavery governments) was the territorial capital, but abolitionists set up an opposition government in Topeka. A mini-Civil War broke out between Border Ruffians who supported slavery and Free-Soilers who opposed it. However, not a large number of slaves ever lived in the territories. John Brown got his start here and the war was what coined the phrase “Bleeding Kansas”.
I suppose it could be that homesteaders in Leavenworth felt obliged to provide shelter for themselves and possibly slaves seeking freedom by building underground facilities. But this seems far-fetched.
Interesting. There should be some artifacts or writings down there to indicate uses. Or so I’d think.