Myths and Legends of our Own Land, by Charles M. Skinner, [1896], at sacred-texts.com
Rappannock River, in Virginia, used to be vexed with shadowy craft that some of the populace affirmed to be no boats, but spirits in disguise. One of these apparitions was held in fear by the Democracy of Essex County, as it was believed to be a forerunner of Republican victory. The first recorded appearance of the vessel was shortly after the Civil War, on the night of a Democratic mass-meeting at Tappahannock. There were music, refreshments, and jollity, and it was in the middle of a rousing speech that a man in the crowd cried, "Look, fellows! What is that queer concern going down the river?"
The people moved to the shore, and by the light of their torches a hulk was seen drifting with the stream—a hulk of fantastic form unlike anything that sails there in the daytime. As it came opposite the throng, the torchlight showed gigantic negroes who danced on deck, showing horrible faces to the multitude. Not a sound came from the barge, the halloos of the spectators bringing no response, and some boatmen ventured into the stream, only to pull back in a hurry, for the craft had become so strangely enveloped in shadow that it seemed to melt into air.
Next day the Democracy was defeated at the polls, chiefly by the negro vote. In 1880 it reappeared, and, as before, the Republicans gained the day. Just before the election of 1886, Mr. Croxton, Democratic nominee for Congress, was haranguing the people, when the cry of "The Black Barge!" arose. Argument and derision were alike ineffectual with the populace. The meeting broke up in silence and gloom, and Mr. Croxton was defeated by a majority of two thousand.