Nearly a century ago, the State of Maryland permitted a group of citizens to establish a memorial cross for veterans of World War I on property owned and maintained by the state. This cross is still there.
Does this Maryland cross violate our Constitution? That very question is currently before the Supreme Court. Maryland-National Capital Park and Planning Commission v. American Humanist Association is an appeal from the Fourth Circuit's decision that the cross is an establishment of religion in violation of the Fourteenth Amendment.
The challenge to the 94-year-old cross (erected in 1925) rests entirely on a 72-year-old precedent, established in Everson v. Board of Education (1947). In Everson, the Court held that the Constitution's Fourteenth Amendment makes both Religion Clauses fully applicable against the states, and therefore, that the federal courts have authority to forbid any state action they deem an establishment of religion.