Mauran v. Insurance Company was a case heard by the United States Supreme Court in 1867. The case involved a dispute between a policyholder and an insurance company over the payment of a claim. The policyholder, Mauran, had taken out a policy with the insurance company to cover the loss of a shipment of goods. When the goods were lost, Mauran filed a claim with the insurance company, but the company refused to pay. Mauran then sued the insurance company in the Supreme Court, arguing that the company had breached its contract by refusing to pay the claim. The Supreme Court agreed with Mauran, ruling that the insurance company had breached its contract and was liable for the claim. The Court also held that the insurance company was liable for any damages caused by its breach of contract. The Court's decision in Mauran v. Insurance Company established the principle that insurance companies must honor their contractual obligations and pay claims when due. This decision has been cited in numerous subsequent cases involving insurance companies and their obligations to policyholders.

In Mauran v. Insurance Company, the Supreme Court was asked to decide whether a policy of insurance issued by an insurer in Massachusetts could be enforced against the insured when it had been assigned to another party without notice or knowledge of the assignment. The majority opinion held that such an assignment was valid and enforceable under Massachusetts law, but Justice Field dissented from this ruling. He argued that since there had been no notice given to the insured about the transfer of rights under their policy, they should not be bound by its terms as if they were aware of them. Furthermore, he noted that allowing assignments without any notification would lead to great injustice for those who are unaware and thus unable to protect themselves from potential losses due to changes in ownership or other circumstances beyond their control.