In common law legal systems, the common law is crucial to understanding almost all important areas of law. For example, in England and Wales, in English Canada, and in most states of the United States, the basic law of contracts, torts and property do not exist in statute, but only in common law (though there may be isolated modifications enacted by statute). As another example, the Supreme Court of the United States in 1877, held that a Michigan statute that established rules for solemnization of marriages did not abolish pre-existing common-law marriage, because the statute did not affirmatively require statutory solemnization and was silent as to preexisting common law.