In the case of McDonald and United States Fidelity and Guaranty Company v. Ples, 1914, the Supreme Court was asked to determine whether a contract for insurance coverage could be considered valid if it had been signed under duress. The plaintiff, Mr. Ples, alleged that he had been forced by his employer (McDonald) to sign an agreement with United States Fidelity and Guaranty Company which would limit his ability to sue for damages in case of injury on the job. He argued that this constituted duress as he feared losing his employment if he did not comply. The court ruled in favor of Mr. Ples stating that any contract entered into under coercion or threat is voidable at the option of the party subjected to such pressure - even when it involves sophisticated commercial entities like insurance companies who are expected to understand their rights better than ordinary citizens. This landmark decision established important legal precedents regarding contractual law and workers' rights protections against coercive practices by employers.

In the dissenting opinion for McDonald and United States Fidelity and Guaranty Company v. Ples, it was argued that the majority's decision to uphold a lower court ruling in favor of Ples contradicted established legal principles regarding contract law. The dissenting justices believed that McDonald and USF&G should not be held liable for damages because they had acted in good faith based on their understanding of an insurance policy agreement with Ples. They contended that any ambiguity in this agreement should have been resolved against Ples as he was responsible for its drafting. Furthermore, they disagreed with the majority's interpretation of relevant state laws, arguing these did not support holding an insurer liable under such circumstances. In conclusion, while recognizing the tragic nature of Mr.Ple’s situation who lost his property due to fire without adequate compensation from his insurers (McDonald & USF&G), they maintained that sympathy could not override fundamental tenets of contract law or justify what they viewed as judicial overreach by both lower courts and now Supreme Court itself.