McCreary County v. American Civil Liberties Union of Kentucky (2005) Definition

In this U.S. Supreme Court decision, the Court ruled that repeated attempts by McCreary County and Pulaski County, Kentucky to post the Ten Commandments inside the counties' courthouses lacked a legitimate secular purpose, violating the establishment clause test laid down in Lemon v. Kurtzman, 403 U.S. 602 (1971) and later decisions.

But see Van Orden v. Perry, 545 U.S. 677 (2005) (plurality decision finding no establishment clause violation when Texas put a Ten Commandments monument on the state capitol grounds).