The Bladensburg Dueling Grounds, located in what is now Colmar Manor, Maryland, is described as a site of lingering supernatural activity due to its violent history. Once known by the ominous names "Blood Run" and "The Dark and Bloody Grounds," the area was a notorious dueling spot in the 19th century where dozens of men were killed in "affairs of honor". Numerous witnesses have claimed to see phantom-like shadows and "fog-shrouded shadows of men of another era" wandering the grounds. A specific apparition is believed to be the ghost of Commodore Stephen Decatur, the celebrated naval hero who was killed in a duel at the grounds in 1820. Witnesses have described seeing a bowed, elderly man dressed in black. According to legend, he may be seeking revenge or trying to warn others away from a similar fate. Some observers have reported seeing figures dressed in black, giving the impression of a ghostly mourning party or funeral procession. A boy at the grounds once reported seeing a vanishing figure of an old man in black.