Creationism teaches that life, and the universe in general, originated in the purposeful action of a being who existed prior to the origins of a created universe. The highly publicized 1925 trial in Scopes v. Tennessee did not establish case law precedent for deciding more recent cases on the teaching of creationism. Two U.S. Supreme Court decisions have established controlling precedents on certain questions, and lower court decisions extend those principles to questions that have emerged in other cases.

In Epperson v. Arkansas (1968), the Supreme Court ruled that an Arkansas statute prohibiting the teaching of evolution was invalid because it unconstitutionally required curriculum to be tailored to particular religious beliefs, in violation of the First Amendment's establishment clause.

In 1987, the Supreme Court held in Edwards ...