This dissertation explores a crucial period in the monetary geography of the Atlantic economy by examining the market for gold and silver coins (specie) in New Orleans between the Panic of 1839 and the U.S. naval blockade of the Confederate port in 1861. Situated at the intersection of global financial history and U.S. economic and business history, the dissertation reconstructs New Orleans’ supply chain of precious metals, shedding light on the port’s strategic role linking mining regions to specie-scarce nations under international bimetallism, and reveals how commission merchants, cotton factors, and merchant banks’ agents relied on metallic liquidity to engage in international trade and financial intermediation during a crucial era for nation-building and economic development in the Americas. The dissertation employs three main research strategies: (1) statistical and geographic analyses of a novel specie imports dataset (the first of its kind in the scholarly literature on specie in the early U.S. economy), extracted from the New Orleans Price-Current, a semi-weekly business newspaper, (2) group profiles and social network analysis of specie importers, leveraging multi-archival research and case studies of individuals, families, and banking and financial entities, (3) historical statistics on U.S. specie imports and Mexican specie production and exports. Chapter 1 reveals New Orleans’ centrality in the antebellum U.S. specie market and its strategic position in securing and shipping specie for the Atlantic economy under international bimetallism. Chapter 2 examines the demand side of the New Orleans specie market by focusing on the port’s cosmopolitan community of specie importers. Foreign residents received more specie than U.S. importers and New Orleans banks combined. The Louisiana Creole commission merchant and cotton factor Edmond Jean Forstall was the market’s key arbitrageur. Importers sorted into “silver barons” and “gold princes:” foreign residents handled mostly Mexican silver, while English residents, Anglo-Americans, and New Orleans banks obtained primarily gold. Chapter 3 focuses on the production and exports of Mexican specie to New Orleans. The port’s commission merchants exported British, Western European, and U.S. goods to Mexico in exchange for pesos (dollars); they reshipped U.S. cotton and Mexican pesos to European markets demanding specie for currency arbitrage operations in Europe and trade with China. Although New Orleans rapidly obtained metallic liquidity amid episodes of financial distress such as the Panic of 1857, its specie supply chain was highly vulnerable to disruptions from geopolitical shocks such as the Mexican-American War (1846-1848) and the U.S. Civil War.