In 1789, we had 13 states. Today we have 50 states. In a federation with 50 states, you're going to have a lot more state line crossings than you'll have in a federation with 13 states. And if every state line crossing creates federal power to act, a huge increase in the number of states will lead to a huge increase in the power of the federal government. And that is essentially what happened in the United States, not only for constitutional reasons, but also for political reasons. So one of the first questions to arise was what is commerce among the several states? And the first famous Supreme Court decision on this was written by John Marshall in a case called Gibbons against Ogden. And what happened in Gibbons against Ogden is that the state of New York gave Ogden a state monopoly, an exclusive state license to run a ferryboat, between Manhattan and New Jersey across the Hudson River. Gibbons decided he wanted to open a competing ferryboat and he got a license from the national government to engage in the coasting trade, which seemed to involve intercoastal communication. Gibbons opened up his ferryboat service to compete with Ogden. Ogden sued him for violating his New York state monopoly. The New York Court of Appeals ruled for Ogden and said that Ogden had the monopoly right to run a boat between Manhattan and New Jersey. And Gibbons appealed to the US Supreme Court, which unanimously reversed the Court of Appeals of New York and ruled for Gibbons. And Chief Justice Marshall, in Gibbons against Ogden said that all commercial intercourse, meaning all contact back and forth across state lines, between people. And so Marshall's opinion in Gibbons against Ogden seems to be limited to a commercial context because there was buying and selling going on with respect to the ferryboat tickets. But it strongly implied that any time people or goods crossed over a state boundary line, there was federal power under the Commerce Clause to regulate that. The federal courts concluded that Congress had power to regulate immigration, in part because immigration involved people crossing an international boundary line and coming into the United States. The Supreme Court in 1903 in a case called Champion against Ames upheld a federal law that made it a crime to ship lottery tickets across a state line. The lottery tickets were not being bought or sold. They were simply being shipped across the state line. But the Supreme Court held that any time there's a state line crossing, the Commerce Clause is implicated. Now that's not necessarily persuasive if you just look at the Commerce Clause, because the word commerce comes from two Latin roots, com which means with and merce, which means to buy or sell. Other English words that derived from the Latin word merce are mercenary, someone you pay to be a soldier; mercantile, an economic policy that a government might pursue; market. Merchandise. It's pretty clear that commerce involved buying and selling and the commerce clause originally probably meant Congress had the power to regulate buying and selling among the states. What the Supreme Court eventually concluded in Champion against Ames in 1903, and then in the cases during the New Deal period was that any travel of persons across state boundary lines or of goods, possessions or property, had to be regulable onto the necessary and proper clause for Congress to be able to carry into execution its power under the Commerce Clause. So it's been settled law since the 1880s that Congress has power over the movement of peoples across international boundary lines and it's been settled law since 1940 that any crossing of property or of people across state boundary lines is regulable.