In 1931, the miners and the mine owners in southeastern Kentucky were locked in a bitter and violent struggle called the Harlan County War. In an attempt to intimidate the family of union leader Sam Reece, Sheriff J. H. Blair and his men, hired by the mining company, illegally entered their home in search of Reece. Reece had been warned in advance and escaped but his wife, Florence, and their children were terrorized. That night, after the men had gone, Florence wrote the lyrics to “Which Side Are You On?” on a calendar that hung in their kitchen. She took the melody from a traditional Baptist hymn, “Lay the Lily Low”, or the traditional ballad “Jack Munro”
Reece supported a second wave of miner strikes circa 1973, as recounted in the documentary Harlan County USA. She and others performed “Which Side Are You On?” a number of times throughout. Reece recorded the song later in life, and it can be heard on the album Coal Mining Women.