commercium

Commerce comes from the Latin commercium (trade, trafficking), from com- (together, with) and merx (goods, wares). The word emphasizes the communal nature of trade: commerce is what happens when people bring goods together. The Latin merx also gives English merchant, mercury (the messenger god who protected traders), mercenary (one who works for pay), and mercy (originally a payment, then a kindness).

English borrowed commerce from French in the sixteenth century. The word carried dignity — commerce was large-scale, international, serious trade. A shopkeeper did not engage in commerce. A trading company did. The East India Company engaged in commerce. The corner grocer engaged in trade. The distinction was about scale and respectability.

The U.S. Constitution's Commerce Clause (Article I, Section 8, Clause 3) gives Congress the power to 'regulate Commerce with foreign Nations, and among the several States.' This single clause has been the basis for much of federal regulatory power. The word 'commerce' in the Constitution has been interpreted by the Supreme Court to cover manufacturing, agriculture, labor relations, civil rights, and health care. The Latin word for 'goods together' now governs enormous areas of American law.

E-commerce — electronic commerce — appeared in the 1990s. The prefix acknowledged that the fundamental activity was the same: buying and selling goods. The medium changed from physical to digital. The Latin root did not. Merx (goods) + com- (together) = commerce. The goods moved online. The togetherness did not change.