This article explores the relation between transatlantic immigration and wealth accumulation in late colonial Mexico City, the chief destination for transatlantic emigrants from Spain. In contrast to the prevalent focus in the literature on networks and transatlantic ties, I argue that economic mobility and thus entry into the upper classes of colonial society depended on the social background of immigrants in their home regions in the peninsula. Human capital rather than social capital was the key determinant explaining why certain regional groups, notably the Basques, succeeded economically as merchants and miners, challenging traditional notions of networks and interconnectedness in Atlantic history and beyond. The findings are grounded in quantitative datasets of Spanish immigrants, overcoming both the biases of anecdotal sources and the methodological intricacy of disentangling the causal relationship between wealth accumulation and social ties.

Starting from the quantitative reconstruction of revenues and expenses of the Royal Treasury in the Yucatan province during the period 1801-1821, the paper shows the transition from an unbalanced regional fiscal structure that depended on colonial transfers (situados) to offset the deficit, to one self-sufficient structure in the context of the Independence War and the liberalism of the Cortes de Cadiz. An autonomy based on the indigenous capitation tax and the fiscal control of foreign trade that was made in the ports of the Yucatan Peninsula.

The constant state of war which dominated the reign of Philip II and part of Philip III'S exerted a growing fiscal demand both on Castile and the American Colonies. The American treasure which opened the doors to credit to finance these campaigns increased substantially over the 17th century. Never the less, the merchants, which controlled the extraction of precious metals and their shipments to the metropolis, established a highly lucrative trade with the Peru and the Philippines which created a constant drain of silver to the Far East. Based on the complaints filed by the Consulado de Sevilla about the competition of Chinese goods and the loss of American silver, the Monarch imposed heavy restrictions on the triangular trade in the Pacific. These restrictions created conflicts with the American viceroys who were interested in this trade and resulted in the generalization of smuggling.