Robert Natelson did extensive research on the meaning of the word “commerce” in relation to the expanded interpretation of the Constitution’s commerce clause favored by progressive legal thinkers. He scoured 17th and 18th century case law, legal works and legal dictionaries, as well as lay usage of the word. His research showed commerce was almost exclusively used in connection with trade – not a broader range of economic activities.
I found that in the case law, judges and counsel used the words commercium and “commerce” in ways similar to those that Professor Barnett identified in lay discourse. The Latin term, which always carries a sense of traffic or exchange, always was used that way in the cases—particularly being applied to merchants and their financial instruments.The more frequently used English word had, with rare exceptions, a similar meaning. It encompassed the buying and selling of items created by others, together with certain closely allied activities. “Commerce” embraced the actions of merchants,factors(commodity brokers), carriers, traffickers with foreign nations, and consignees. The courts connected shippers and navigators with “commerce,” and regulation of navigation was closely associated with regulation of commerce—which shows that Chief Justice Marshall’s view of the matter in Gibbons v. Ogden was solidly supported by precedent. This also answers a question Professor Mark R. Killenbeck’s posed a few years ago: How could the First Congress think it could regulate in detail the conduct of sailors unless it had adopted a “substantial effects” view of the commerce power? That answer is that there was no need for a “substantial effects” test, for regulating navigation had long been part of regulating commerce.
Commerce benefited agriculture and manufacture by circulating their products, but it did not include agriculture or manufacture. Jurists compared commerce to an enormous circulatory system, carrying articles throughout the entire Body Politic, as the blood in the human body carries oxygen and nourishment. Thus, like the American Founders, English lawyers and judges understood the tight interrelationship between commerce and other parts of the economy, yet they were careful to distinguish them conceptually.
You can read Natelson’s complete paper here.