McCreary County v. American Civil Liberties Union of Kentucky, 545 U.S. 844 (2005), was a case argued before the Supreme Court of the United States on March 2, 2005.

In a suit brought by the American Civil Liberties Union of Kentucky, the United States Court of Appeals for the Sixth Circuit held that the displays—in this case, a Ten Commandments display at the McCreary County courthouse in Whitley City, Kentucky and a Ten Commandments display at the Pulaski County courthouse—were unconstitutional.

The district court, following the Lemon v. Kurtzman test, entered a preliminary injunction against the newly modified exhibits, finding that there was no secular purpose behind the inherently religious displays.

The new posting, entitled "The Foundations of American Law and Government Display", consisted of nine framed documents of equal size.

One set out the Commandments explicitly identified as the "King James Version", quoted them at greater length, and explained that they have profoundly influenced the formation of Western legal thought and the American nation.

In addition to the Commandments, the counties added historical documents containing religious references as their sole common element.

The additional documents included framed copies of the Magna Carta, the Declaration of Independence, the Bill of Rights, the lyrics of the Star Spangled Banner, the Mayflower Compact, the National Motto, the Preamble to the Kentucky Constitution, and a picture of Lady Justice.

The court took proclaiming the Commandments' foundational value as a religious, rather than secular, purpose under Stone v. Graham and found that the counties' asserted educational goals crumbled upon an examination of this case's history.

First, the Court reiterated its previous holding in Stone v. Graham that the Commandments are "undeniably a sacred text in the Jewish and Christian faiths" and that their display in public classrooms "violated the First Amendment's bar against establishment of religion."

Justice O'Connor expressed her own views of the controversy in a concurring opinion: It is true that many Americans find the Commandments in accord with their personal beliefs.

There is no list of approved and disapproved beliefs appended to the First Amendment–and the Amendment's broad terms ("free exercise," "establishment," "religion") do not admit of such a cramped reading.

[18]Justice Scalia wrote a dissenting opinion, in which he argued that public acknowledgement of the God of Christianity, Judaism, and Islam is permissible under the First Amendment: Besides appealing to the demonstrably false principle that the government cannot favor religion over irreligion, today's opinion suggests that the posting of the Ten Commandments violates the principle that the government cannot favor one religion over another .

Instead, they claimed that the Sixth Circuit Court had failed to follow the majority's comment allowing government to reform the reasoning of a display to render it constitutional.