In the 1910 case of International Textbook Company v. Peterson, the U.S. Supreme Court ruled in favor of International Textbook Company, stating that its business practices did not violate Iowa's anti-trust laws. The company offered correspondence courses and sold textbooks to students across state lines, which was challenged by Peterson under Iowa law prohibiting corporations from engaging in more than one type of business activity. However, the court held that these activities were part of a single line of trade rather than separate businesses as defined by local legislation. Furthermore, it found no evidence suggesting any intent or effect to restrain trade or establish monopoly power on behalf of International Textbook Company.

In the dissenting opinion for International Textbook Company v. Peterson, Justice Harlan argued that the majority's decision was an overreach of federal power and a violation of states' rights. He contended that there was no constitutional basis for preventing a state from regulating its own internal commerce as it saw fit, including imposing restrictions on corporations operating within its borders. Furthermore, he believed that the Court had misinterpreted the Commerce Clause by applying it to activities not directly related to interstate trade or commerce. In his view, this interpretation could potentially lead to federal interference in areas traditionally under state control such as education and labor laws. Thus, he disagreed with the majority's ruling which held that Iowa’s requirement for out-of-state companies to maintain an office within Iowa if they wanted to conduct business in their state violated the Commerce Clause of U.S Constitution.