Epperson appealed the State Supreme Court's reversal to the United States Supreme Court. Eugene R. Warren presented arguments for the appellant, Epperson, and Don Langston, an Assistant Attorney General for Arkansas, argued on behalf of the state of Arkansas. Both Langston and the State Appeal Court focused on the power given to states to set curriculum standards, and did not delve far into the subject of evolutionary theory itself nor to the boundaries between church and state.[5]
U.S. Supreme Court found the reasons given in the Arkansas reversal were in error. They went on to say the clear purpose of the Arkansas statute against the teaching of evolution was to protect a particular religious view, and was thus unconstitutional. In a decision written by Justice Abe Fortas, the Court held,
The overriding fact is that Arkansas’ law selects from the body of knowledge a particular segment which it proscribes for the sole reason that it is deemed to conflict with a particular religious doctrine; that is, with a particular interpretation of the Book of Genesis by a particular religious group.[6]
The Court found that not only was the state prohibited from advancing or protecting a particular religious view, but that,
[T]he state has no legitimate interest in protecting any or all religions from views distasteful to them.[6]
Justice Hugo Black issued a separate opinion to overturn the Arkansas law, finding the law unconstitutionally "vague" rather than an unconstitutional religious infringement. While agreeing with the majority to reverse the State Appeal Court decision, his opinion details his dissent from the majority over the First Amendment