This paper examines the structural relationship between U.S. agricultural exports, foreign GDP growth, and real exchange rate volatility, and the impact of exogenous shocks on the evolution of export growth to examine the sector's international competitiveness and opportunities for export extensification. The long- and short-run dynamics of export demand are analyzed within the structural cointegrating vectorautoregressive framework. Principal findings are that: 1. Exports of high-value processed agricultural products are more sensitive to changes in foreign income and exchange rate fluctuations than exports of low-value grains and bulk commodities. Specifically, a 10% growth in trade-adjusted GDP across all importing countries leads to a 7.8% increase in U.S. exports of bulk commodities compared to 33% increase in exports of high-value processed commodities. Similarly, a 10% increase in the value of the trade-weighted exchange rate (i.e., an appreciation of the U.S. dollar) reduces bulk exports by 8.4% compared to a whopping 35% decline in high-value processed food exports; 2. In response to exogenous shocks, deviations from the predicted equilibrium level of exports are corrected at a much faster rate for grains and other bulk commodity exports than export of high value commodities. For example, more than 75% of the disequilibrium in aggregate bulk commodity exports is corrected within one year; less than 15% of the disequilibrium in high-value processed exports is corrected within a year. 3. The present concentration of U.S. agricultural commodity exports to a few developed countries is increasingly problematic, U.S. agricultural exports may benefit not only from policies intended to increase trade with existing developing country importers but also from policies that aim to export agricultural commodities to emerging markets. Our paper also highlights the importance of including the long-run relationship when modeling the short-run dynamics.