Although arranged by John Baptiste Calkin in 1872, the song “I Heard on the Bells on Christmas Day” was actually based on the poem “Christmas Bells,” written by American poet Henry Wadsworth Longfellow. A series of events in Longfellow’s life led him to pen the poem. In 1861, the Civil War broke out, causing hatred, racism and division throughout the country. That same year, his wife died tragically. Two years later, his son was severely wounded fighting in the Civil War. The following year, 1864, President Lincoln was reelected, the Civil War raged on, and Longfellow wrote the carol.