The scholar examining nineteenth-century Central American (here defined as including Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica) foreign relations, particularly foreign trade relations, constantly finds quite positive statements regarding British, French, and United States economic power in Central America. These often allege political domination of the individual nations through foreign economic influences. Invariably such claims are based either upon “common knowledge,” without supportive data, or upon data of a highly selective, unsystematic, or arbitrary nature. Confronted with the choice of accepting or challenging these allegations, the scholar may choose the previous “general wisdom,” “create” his own “wisdom,” or institute as systematic a study of foreign economic trade and navigation ties as existing data sources permit. For the scholar wishing to undertake a detailed study, this essay will describe the location, abundance, reliability, and accuracy of data relative to nineteenth-century Central American trade and navigation as encountered in sources from Guatemala, Costa Rica, El Salvador, Nicaragua, Honduras, the United States, Great Britain, France, Hamburg (until 1873), Bremen, the German Empire (beginning about 1880), Spain, Italy, the Netherlands, and Belgium. While the following discussion focuses upon the use of United States and European archives and the statistical and commercial serials for gathering data on Central American trade and maritime activity, obviously many of these same sources, archives, or serials possess identical data for most other Latin American countries or regions.