In the United States v. Wickersham case of 1905, the Supreme Court ruled on a dispute over land ownership in Alaska. The plaintiff, Wickersham, claimed that he had purchased a plot of land from an Alaskan native who had been living there for many years and thus held "aboriginal title" to it. However, the U.S government argued that since Alaska was acquired by treaty with Russia in 1867 and no rights were reserved for natives within this treaty, all unappropriated lands belonged to them as public domain lands. The court sided with the government stating that aboriginal title is not recognized unless explicitly acknowledged by Congress or through treaties which wasn't done when acquiring Alaska from Russia. Therefore, any sale of such land without governmental approval would be invalid under federal law regardless if it's inhabited or improved upon by indigenous people. This ruling reinforced existing legal precedent regarding Native American tribal sovereignty and property rights - namely Johnson v McIntosh (1823) where private citizens cannot purchase lands directly from Native Americans but only via federal government.

In the dissenting opinion for United States v. Wickersham, Justice Harlan argued that the majority's decision to uphold a lower court ruling dismissing an indictment against a postal worker accused of stealing mail was incorrect. He believed that Congress had intended to criminalize all thefts from the mail, not just those involving registered items or packages containing valuables as interpreted by the majority. According to him, such interpretation would leave many types of mail unprotected and create a loophole in which postal workers could steal with impunity if they were careful only to target unregistered letters or parcels without valuable contents. This view contradicted his understanding of Congressional intent behind relevant statutes - protecting all mails from theft regardless of their content or registration status.