United States Supreme Court (1885), in the case of Murphy v. Ramsey & Others, 144 U.S. 15, 45 (1885), gave its opinion:
Every person who has a husband or wife living … and marries another … is guilty of polygamy, and shall be punished.… Certainly no legislation can be supposed more wholesome and necessary in the founding of a free, self-governing commonwealth … than that which seeks to establish it on the basis of the idea of the family, as consisting in and springing from the union for life of one man and one woman in the holy estate of matrimony; [Marriage is] the sure foundation of all that is stable and noble in our civilization; the best guarantee of that reverent morality which is the source of all beneficent progress in social and political improvement.
United States Supreme Court (1890), in the case of The Church of Jesus Christ of Latter Day Saints v. United States, 136 U.S. 1 (1890), forbade the practice of polygamy in the United States, stating:
It is contrary to the spirit of Christianity and the civilization which Christianity has produced in the Western world.
As quoted in: William J. Federer, Great Quotations: A Collection of Passages, Phrases, and Quotations Influencing Early and Modern World History Referenced According to Their Sources in Literature, Memoirs, Letters, Governmental Documents, Speeches, Charters, Court Decisions and Constitutions (St. Louis, MO: AmeriSearch, 2001).