Louisiana has become the first US state to order all classrooms, from elementary to university level, to display a poster of the Ten Commandments. The Republican-backed measure describes the commandments as foundational to state and national government. The law is expected to face challenges from civil rights groups, who will argue that it violates the First Amendment, which prohibits government establishment of religion. The commandments must be in large, readable font, next to a ‘context statement’ about their historical role in American education. There have been numerous legal battles over the display of the Ten Commandments in public buildings, including schools, courthouses and police stations. In the past, the Supreme Court has struck down similar laws, ruling that displaying the Ten Commandments in public schools lacked a secular legislative purpose and was inherently religious.