This article reports on archaeological investigations conducted at the Thaddeus Stevens and Lydia Hamilton Smith Site in Lancaster, Pennsylvania. The Stevens and Smith Site stands in the footprint of Ii proposed convention center and hotel complex, and will be partially destroyed by the construction. Stevens, a noted anti-slavery legislator, and Smith, his African American housekeeper and companion, are reputed to have been actively involved in the Underground Railroad during the 1850s. While little concrete evidence exists to corroborate the degree to which Stevens and Smith assisted fugitives escaping from enslavement, our excavations uncovered a modified cistern that may have been used as a hiding place. The evidence supporting that hypothesis is presented here.