King Cotton and his Mexican Pesos: The Production and Exports of Mexican Silver Pesos to New Orleans (1821-1861).This paper focuses on the production and exports of Mexican silver pesos to the United States and New Orleans from Mexico’s independence (1821) through the U.S. Civil War by responding to a U.S. Treasury letter that went unanswered for 170 years. First, I describe the changes in the production and exports of Mexican silver pesos during the country’s transition from Spanish rule to independence. Then, I examine Mexican silver pesos production and exports between 1821 and 1870 with historical statistics and qualitative evidence. Next, I examine the role of New Orleans as a “natural depot” for Mexico’s silver and the changing geography of the port’s silver imports between 1839 and 1861. The chapter sheds light on the New Orleans importers of Mexican specie, true “silver barons” of the Cotton Kingdom. Concluding remarks summarize the paper's findings.