We examine the origins, persistence, and economic consequences of institutional structures of agricultural production. We compare farms in the Argentine Pampas and US Midwest, regions of similar potential input and output mixes. The focus is on 1910-1914, during the international grain trade boom and when census data are available. The Midwest was characterized by small farms and family labor. Land was a commercial asset and traded routinely. The Pampas was characterized by large landholdings and use of external labor. Land was a source of status and held across generations. Status attributes could not be easily monetized for trade, reducing market exchange, limiting entry, and hindering farm restructuring. Differing land property rights followed from English and Spanish colonial and post-independence policies. Geo-climatic factors cannot explain dissimilarities in farm sizes, tenancy, and output mixes, suggesting institutional constraints. Midwest farmers also were more responsive to exogenous signals. There is evidence of moral hazard on Pampas farms. Conjectures on long-term development are provided. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.