This article analyses various transformations that took place within the Spanish colonial trade before the implementation of the 1778 free trade regulations. Firstly it shows the changes in the pattern of trade caused by the adoption in 1739 of the system of register ships (single «registered» ships), which resulted in the cancellation of the traditional system of fleets. Secondly it examines the role of transatlantic mail in shaping a new, increasingly retail-oriented pattern of trade. Finally, it deals with the evolution of the flow of commercial information crossing the Atlantic, stressing the growing impact of fashion. The primary sources used are mainly letters belonging to Spanish merchants that were confiscated by the British during the eighteenth-century wars.
