This paper examines the impact on agricultural development of the introduction of barbed wire fencing to the American Plains in the late nineteenth century. Without a fence, farmers risked uncompensated damage by others' livestock. From 1880 to 1900, the introduction and near-universal adoption of barbed wire greatly reduced the cost of fences, relative to the predominant wooden fences, especially in counties with the least woodland. Over that period, counties with the least woodland experienced substantial relative increases in settlement, land improvement, land values, and the productivity and production share of crops most in need of protection. This increase in agricultural development appears partly to reflect farmers' increased ability to protect their land from encroachment. States' inability to protect this full bundle of property rights on the frontier, beyond providing formal land titles, might have otherwise restricted agricultural development. (c) 2010 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology..

This article examines the historical impact of railroads on the U.S. economy, with a focus on quantifying the aggregate impact on the agricultural sector in 1890. Expansion of the railroad network may have affected all counties directly or indirectly—an econometric challenge that arises in many empirical settings. However, the total impact on each county is captured by changes in that county’s “market access,” a reduced-form expression derived from general equilibrium trade theory. We measure counties’ market access by constructing a network database of railroads and waterways and calculating lowest-cost county-to-county freight routes. We estimate that county agricultural land values increased substantially with increases in county market access, as the railroad network expanded from 1870 to 1890. Removing all railroads in 1890 is estimated to decrease the total value of U.S. agricultural land by 60%, with limited potential for mitigating these losses through feasible extensions to the canal network or improvements to country roads.