In the United States, until the mid-19th century, common-law marriages were recognized as valid, but thereafter some states began to invalidate common-law marriages. Common-law marriages, if recognized by law, are valid, notwithstanding the absence of a marriage license; this becomes an issue in the settlement of decedents' estates. North Carolina and Tennessee (which was originally western North Carolina) never recognized marriage at the common law as valid without a license unless entered into in other states. They have always recognized otherwise valid marriages (except bigamous, polygamous, interracial, or same-sex) entered into in conformity with the law of other states, territories and nations.