In the United States v. Barber case of 1910, the Supreme Court examined whether a federal law that imposed taxes on foreign-built yachts violated the Commerce Clause of the Constitution. The plaintiff, Barber, was a yacht owner who argued that this tax unfairly discriminated against him and others like him because it only applied to those with vessels constructed outside of America. However, in its decision, the court upheld Congress's power to impose such taxes under its constitutional authority to regulate commerce with foreign nations. It ruled that while Congress cannot use taxation as a means to create an unfair advantage for domestic industries over their foreign counterparts or prohibit international trade altogether; it can levy duties on imported goods - including yachts - as part of its broader regulatory powers over interstate and international commerce.

In the dissenting opinion for United States v. Barber, Justice Harlan argued that the majority's interpretation of the law was too narrow and failed to consider its broader implications. He contended that Congress had intended to regulate all commerce between states, not just those transactions involving physical goods crossing state lines. Therefore, he believed that a transaction conducted by telegraph should be considered interstate commerce and subject to federal regulation even if no physical goods were involved in the transaction itself. Furthermore, he disagreed with the majority's assertion that such transactions did not affect other states or interfere with their rights; instead, he argued they could have significant economic impacts on other states and therefore fell under Congress' regulatory power.