In Leighton v. United States (1895), the U.S Supreme Court ruled on a case involving an individual named George E. Leighton who was convicted of embezzlement while serving as an officer for a national bank in Massachusetts. The main issue at hand was whether or not certain evidence should have been admitted during his trial, specifically two letters written by him to the Comptroller of Currency that were used to establish intent and knowledge of wrongdoing. Leighton argued that these letters were improperly admitted into evidence because they were compelled self-incriminating testimonies, which would be protected under the Fifth Amendment's protection against self-incrimination. However, the court disagreed with this argument stating that he had voluntarily provided these statements without any compulsion from government officials. Furthermore, it held that even if there had been some form of compulsion involved in obtaining these statements, it wouldn't matter since they weren't obtained through criminal proceedings but rather administrative ones related to his role as a bank officer. Therefore, based on its interpretation of what constitutes 'compelled' testimony and how protections against self-incrimination apply within different contexts such as administrative versus criminal proceedings; the court upheld Leighton’s conviction.

In the dissenting opinion for Leighton v. United States, Justice Harlan disagreed with the majority's interpretation of the Sherman Anti-Trust Act and its application in this case. He argued that Congress did not intend to prohibit all contracts or agreements that might indirectly or remotely affect commerce among states when they enacted this law. Instead, he believed it was meant to prevent arrangements designed to monopolize trade directly and substantially interfere with interstate commerce. In his view, a contract between two individuals for personal services could not be considered as such an arrangement unless it involved some form of restraint on commercial competition beyond what is necessary for their mutual benefit and protection. Therefore, he concluded that Mr.Leighton’s agreement should not fall under the purview of federal antitrust laws because it didn't involve any attempt at monopoly nor did it impose unreasonable restraints on trade or commerce among several states.