Blue Light Federalists

Blue Light Federalists were members of the Federalist Party in New England who were alleged to have collaborated with the Royal Navy during the War of 1812. They supposedly used blue lanterns to alert British warships to American blockade runners, earning the name "blue light." The term was later applied more broadly by war hawks in the Democratic-Republican Party to refer to all Federalist opponents of the war, including tax protesters and secessionists.

During a thwarted attempt to run the British blockade at New London, Connecticut, Commodore Stephen Decatur claimed to have seen blue lights flashing from the Connecticut shore. He later alleged that these were signals to the British fleet to alert them of his plans.

Major general James Wilkinson accused the presiding judge of the St. Lawrence County, New York, Nathan Ford of signaling to British forces using a blue lantern during the invasion of Canada. Ford, a Federalist, was charged with treason and brought before the United States district court in New York City, but the charges were dismissed by the district court judge .