Geography, timing, and technology: a GIS-based analysis of Pennsylvania's iron industry, 1825-1875

This article examines key questions about the development of Pennsylvania's mid-nineteenth-century iron industry. The analysis is based on new data and exhaustive examination of previously underutilized sources within the framework of a geographic information system (GIS). Hypotheses are tested on the timing of adoption of mineral-fuel technologies across the state; the temporal relationships between investment in ironworks, business cycles, and tariff policy; the substitutability of different types and qualities of iron; how transport costs affected iron prices; and the geographical segmentation of iron markets in the antebellum period. The findings reveal complex and dynamic patterns of regional economic development.