Bricks and Brick Making at the Harriet Tubman Home: Archaeology, History and Neutron Activation Analysis

This archaeological study examines a brick kiln and use of brick at Harriet Tubman’s farmsteads in Auburn and Fleming, New York. The study begins by presenting evidence of a brick kiln on the Harriet Tubman Home for the Aged (HTH) property and proceeds to a refined analysis of brick and clay element composition using Neutron Activation Analysis (NAA) to define source from structures and features across the property. The study uses findings relating to brick use to examine and the social and economic roles of brick making on Tubman’s properties and in the local community. The brick kiln on the HTH property was identified through a combination of surface survey, remote sensing, shovel testing, and excavation. This study analyzes each of these data sets using an interpretive contextual approach to present descriptive, graphic and statistical information on the Tubman brick kiln site. It then goes on to take a closer look at the composition of brick and clay samples from the brick kiln site (Locus 6) in relation to brick use across the Tubman property. One question that arose during the course of analysis is: Are the brick used in the construction of Tubman’s residence and barn (Locus 1), and buildings on the adjacent Harriet Tubman Home for the Aged property, including a dormitory/infirmary called John Brown Hall (Locus 3), and brick foundation next to a wood frame house (Locus 2) made of locally produced brick? This question is addressed using neutron activation analysis. Archaeological reconnaissance facilitated the identification and excavation of a brick kiln previously undocumented on this National Landmark property. This study reports on the brick kiln structure and uses a combination spatial, material, and historical analyses to generate maps and distribution maps as well as descriptive reconstructions of the kiln and its operations. The element composition of 51 brick and clay samples were examined using NAA. These samples were run at the MURR Archaeometric Laboratory with funding from a Crown Scholar’s grant and a research grant subsidy from NSF Grant (#0802757). Samples from the brick kiln and from structures and features on Tubman’s properties were selected in order to yield data from each locus and feature on the Tubman properties and from adjacent properties associated with brick making. The samples also included materials from known off site sources. The NAA analysis indicates that nearly all of the clay samples project an element and chemical composition that is consistent with a local production source. However, no significant statistical differentiation can be made between the brick from the Tubman site brick kiln and the nearby Saunders brick kiln (200 meters to the south). Brick used in construction of structures on the Tubman properties all fall within what has been defined as an “Auburn” brick and clay cluster. Three exotic brick were defined and verified as having element composition that is not consistent with the local clay and brick. However, two brick from Syracuse show similar composition to the Auburn cluster and may well have been made from clay deriving from the same glacial deposits and drainage area. Finally, clay marbles from the site were probably not made locally, but rather probably originally soda bottle stoppers broken out of bottles from a range of exotic manufacture sources. Finally, the study examines the findings in relation to the broader Tubman archaeological and historical study. It concludes with a discussion of the role of the brick kiln in the broader social and economic networks reflected by the HTH properties and the life of Harriet Tubman in Central New York