In New York Mutual Life Insurance Company v. Armstrong, Administratrix, the United States Supreme Court was asked to decide whether a life insurance policy was validly issued. The policy was issued to the deceased's wife, who was the administratrix of the estate. The insurance company argued that the policy was invalid because the deceased had not disclosed a prior medical condition on the application. The Court held that the policy was valid because the deceased had not made any false representations on the application. The Court also held that the insurance company was estopped from denying the policy because it had accepted the premium payments and had not informed the deceased of any potential problems with the policy. The Court concluded that the insurance company was liable for the policy proceeds. This case established that an insurance company cannot deny a policy based on a prior medical condition if the insured has not made any false representations on the application.

In New York Mutual Life Insurance Company v. Armstrong, Administratrix, the Supreme Court was asked to decide whether a life insurance policy issued in 1864 by an Illinois company to a resident of Missouri could be enforced after the death of the insured in 1877. The majority opinion held that it could not because at that time there were no laws allowing such policies to be enforced outside their state of origin. Justice Field dissented from this ruling and argued that since both states had adopted similar statutes regarding life insurance contracts, they should have been considered valid and enforceable regardless of where they originated from. He further noted that if these contracts were invalidated on jurisdictional grounds then it would create uncertainty for all parties involved as well as lead to potential injustice when one party is unable or unwilling to comply with its obligations under the contract due solely based on its place of origin.