One reportedly coded Underground Railroad song is "Follow the Drinkin' Gourd". The song's title is said to refer to the star formation (an "asterism") known in America as the Big Dipper and in Europe as The Plough. The pointer stars of the Big Dipper align with the North Star. In this song the repeated line "Follow the Drinkin' Gourd" is thus often interpreted as instructions to escaping slaves to travel north by following the North Star, leading them to the northern states, Canada, and freedom: The song ostensibly encodes escape instructions and a map from Mobile, Alabama up the Tombigbee River, over the divide to the Tennessee River, then downriver to where the Tennessee and Ohio rivers meet in Paducah, Kentucky.