Definition
Commerce is the exchange of goods, services, labor, transportation, and other commodities between persons, businesses, or nations with the purpose of realizing value or profit. The term operates at several levels of legal meaning:
1. Private-law sense: Any reciprocal transaction in which one party delivers a thing of value — goods, merchandise, or a service — and the other provides consideration in return. This sense encompasses the specific contracts of sale, barter, and exchange and forms the conceptual basis for commercial law.
2. Constitutional sense: The broad category of economic and social intercourse that Congress is empowered to regulate under the Commerce Clause of the U.S. Constitution (Art. I, § 8, cl. 3). Federal courts have interpreted this power expansively over time. In its modern form it reaches not only the physical movement of goods across state lines but also the channels and instrumentalities of interstate commerce, activities that substantially affect interstate commerce, and — in an evolving body of doctrine — the cumulative economic impact of local activity on national markets.
3. Statutory sense: Many federal and state statutes define commerce for their own purposes, sometimes narrowly (limiting the term to movement of physical goods) and sometimes broadly (extending it to telecommunications, financial transactions, or digital activity). These definitions are not uniform and must be read within each statute's own framework.
Common Language
Modern common usage (Wiktionary): To carry on trade; to traffic. Also, to hold conversation or communicate.
Historical common usage (Webster's 1913): The exchange or buying and selling of commodities, especially on a large scale between different places or communities; extended trade or traffic. Also, social intercourse and dealings between persons.
The legal term tracks the commercial senses closely, so the gap is not in ordinary meaning but in scope and constitutional weight. Where a non-lawyer hears "commerce" and thinks of buying and selling, the constitutional lawyer hears a jurisdictional trigger — the threshold question of whether federal power may be exercised at all. The social-intercourse meaning from Webster's has no legal traction and should not be imported into legal contexts.
Common Confusion
Commerce is frequently conflated with trade, but the historical dictionaries flag a real distinction: trade refers to habitual dealing in a particular commodity, while commerce is the broader genus covering all exchange, including transportation, communication, and the infrastructure that makes exchange possible. Anderson notes that "transportation is the means by which commerce is carried on" — transportation is therefore within commerce, not separate from it. This distinction matters enormously in Commerce Clause analysis, where the power to regulate the channels and instrumentalities of commerce is treated as a distinct and historically recognized category.
Commerce should also not be confused with commerce clause doctrine. The term commerce identifies the subject matter; the Commerce Clause and its associated doctrines (including the dormant Commerce Clause) determine the legal consequences of that classification.
Core Elements
For constitutional purposes, the Supreme Court has structured Commerce Clause analysis around three recognized categories of activity Congress may regulate:
— Channels of interstate commerce: the roads, waterways, airways, and communications networks through which commerce moves.
— Instrumentalities of interstate commerce: the persons, machines, and vehicles that move through those channels, even if a particular transaction is wholly intrastate.
— Activities that substantially affect interstate commerce: local activity that, in the aggregate, has a substantial economic effect on commerce among the states. This is the most contested and most litigated category.
This three-part framework, sharpened in United States v. Lopez (1995) and United States v. Morrison (2000), is the operative test in modern federal Commerce Clause cases. Researchers working in pre-Lopez materials will find doctrine that is considerably more permissive and less structurally organized.
Recognized Forms
/SUBTYPES
Interstate commerce: Commerce crossing or substantially affecting state lines. The primary subject of federal regulatory power under the Commerce Clause.
Intrastate commerce: Commerce occurring entirely within one state. Subject to state regulation, except where federal law preempts or where the activity substantially affects interstate commerce.
Foreign commerce: Commerce between the United States and foreign nations. Regulated by Congress under the same clause; analytically similar to interstate commerce but with additional treaty and foreign-affairs dimensions.
Commerce in the trademark sense: Under the Lanham Act, use "in commerce" is a statutory prerequisite to federal trademark registration and enforcement. This is a term of art with its own body of case law and should not be read interchangeably with the constitutional definition.
Why It Matters in Research
The single greatest trap for researchers is assuming a uniform definition across legal contexts. Commerce means something different in a contract-law treatise, a Commerce Clause brief, a federal regulatory statute, and a Lanham Act trademark case. Always identify which sense is operative before proceeding.
Historical sources predate the major constitutional turning points. Bouvier notes that congressional power over commerce "keeps pace with the progress of the country and adapts itself to new developments" — a principle visible in early telegraph cases — but Bouvier could not anticipate the post-New Deal expansion under Wickard v. Filburn (1942) or the retrenchment signaled by Lopez and Morrison. Sources from the Lochner era (roughly 1890–1937) reflect a substantially narrower conception of commerce that the courts have largely rejected but that remains relevant for understanding the doctrinal history.
Constitutional_47 in the encyclopedia traces the arc from Gibbons v. Ogden through the New Deal transformation to the Lopez/Morrison framework — essential reading before working with Commerce Clause materials from any period. Constitutional_48 covers the dormant Commerce Clause, the negative implication of the clause that restricts state power to burden or discriminate against interstate commerce — a doctrine that runs parallel to the affirmative Commerce Clause and requires separate analysis.
For intellectual property researchers, ip_69 addresses the Lanham Act's "use in commerce" requirement, which turns on a specific statutory definition and a body of administrative and judicial interpretation that has nothing to do with whether a business activity is large, interstate, or economically significant in the antitrust sense.
Historical Dictionary Support
The historical dictionaries converge on the core private-law definition: commerce is the facilitation of exchange — of goods, products, labor, transportation — with intent to realize a profit. Bouvier and Black's both cite Pardessus as authority for this definition, reflecting the French commercial law influence on nineteenth-century American treatise writing. Rapalje & Lawrence emphasizes the distinction between commerce (the broader genus, involving international exchange of surpluses) and trade (more specific, habitual dealing). Anderson's is notable for its forward-looking expansion: "labor, transportation, intelligence, care, and various mediums of exchange become commodities and enter into commerce" — language that anticipates the modern constitutional understanding better than most of its contemporaries.
Burrill's emphasizes the strict-sense definition (traffic in merchandise) and relies on Latin etymology to establish the original mercantile meaning. This strict sense was the dominant one in early constitutional interpretation and explains why nineteenth-century courts struggled with whether railroads, telegraphs, and manufactured goods were truly within the commerce power.
What the historical dictionaries largely miss: the dormant Commerce Clause as a distinct doctrine, the substantial-effects test, the aggregation principle, and any sense that the definition of commerce could itself be a contested constitutional question rather than a settled factual premise. Researchers should treat these sources as capturing the private-law baseline and the early constitutional intuition, not as reliable guides to modern doctrine.
Jurisdictional Note
The constitutional definition of commerce is a matter of federal law and applies uniformly, though its application to specific facts is heavily litigated. State statutes that use the word commerce may define it differently from federal usage; some state antitrust and consumer protection laws, for example, restrict the term to intrastate transactions. In trademark and trade regulation matters, statutory definitions govern and must be located and applied independently.
Encyclopedia Cross-Reference
The Commerce Clause — From Gibbons to Lopez and Morrison (Constitutional Law Encyclopedia, constitutional_47)
The Dormant Commerce Clause — State Discrimination and Burden on Interstate Commerce (Constitutional Law Encyclopedia, constitutional_48)
Trademark Use in Commerce and the Use Requirement (Intellectual Property Encyclopedia, ip_69)