Family law is that body of law having to do with creating, ordering, and dissolving marital and family groups. Although the exact scope of family law is given differently by different authors, at its core family law is concerned with such issues and events as marriage, separation, divorce, alimony, custody, child support, and adoption, as well as the more arcane topics of annulment, paternity, legitimacy, artificial insemination, and surrogate parenting.

This entry on family law in the United States should be read with two important caveats in mind. First, it is somewhat misleading to write of "United States" family law. Because the power to regulate domestic life is not one of the powers delegated to the federal government by the Constitution, in the United States most family law has been "a virtually exclusive province of the states" (Sosna v. Iowa, 419 U.S. 393 [1975]). Despite considerable variation in...