BLADENSBURG, Maryland — The Bladensburg Peace Cross, which honors 49 Prince George’s County residents who were killed in World War I, is being challenged as a violation of the separation of church and state. Plaintiffs say the 40-foot-tall cross, standing on government property, is an endorsement of Christianity. Defenders of the monument argue it is a secular remembrance honoring veterans. Oral arguments will be heard in the Supreme Court Wednesday.