In the case of United States v. Realty Company (1895), the U.S Supreme Court dealt with a dispute over land ownership in St. Louis, Missouri between private entities and the federal government. The land had been originally granted to certain individuals by Spain before it was acquired by America through Louisiana Purchase in 1803. After several transfers, it ended up being owned by Realty Company which claimed title based on these Spanish grants. However, the US Government argued that this claim was invalid as Congress had never confirmed these Spanish grants after acquiring Louisiana territory from France. The court held that although there were some irregularities in how titles were transferred among various private parties over years, they did not affect validity of original Spanish grant or subsequent confirmation of those rights by American authorities during early 19th century when Missouri became part of Union as a state. Therefore, despite objections raised by US Government about procedural issues related to transfer and registration of property rights under different legal systems (Spanish colonial law vs American common law), Supreme Court upheld legality and legitimacy of Realty Company's claim for ownership based on historical records showing continuity and recognition for their property rights since time when area was still under control of Spain.

In the dissenting opinion for United States v. Realty Company, Justice Harlan disagreed with the majority's interpretation of the Sherman Antitrust Act and its application in this case. He argued that Congress intended to prevent all contracts or combinations which restrain trade, regardless of their reasonableness or unreasonableness. In his view, any agreement that restricts competition is inherently harmful to public interest and should be deemed illegal under federal law. Furthermore, he contended that it was not within the Court's purview to decide whether a particular restraint on trade was reasonable or unreasonable; such determinations were better left to legislative bodies rather than judicial ones. By allowing certain restraints on trade based on their perceived reasonableness, Harlan believed that the Court had effectively rewritten an act of Congress - something it did not have authority to do.