In a 7-2 decision, the US Supreme Court upheld the constitutionality of a 40-foot cross in Bladensberg, MD, that was part of a World War I memorial. The Court held that the history and context of a religious symbol can result in additional, secular meanings being attributed to the symbol. They also held that longstanding memorials, henceforth, will have the presumption of constitutionality.
The case itself:
The American Legion v American Humanist Association
From the American Legion: Bladensburg ruling 'victory for freedom'
From the American Humanist Association: Supreme Court Approves Publicly Funded Christian Favoritism