The Battle Hymn of the Republic is perhaps one of the most stirring patriotic songs ever written—closely identified with the Union cause in the Civil War. In November 1861, Julia Ward Howe was touring Union army camps with her husband, a medical doctor, along with a minister friend of theirs.
Some soldiers were singing popular war songs and Reverend Clarke suggested to Mrs. Howe that she might write new lyrics to one of the songs—resulting in the lyrics of the now famous, Battle Hymn of the Republic. Julia Ward Howe's lyrics draw extensively on biblical imagery, including Isaiah 27:1: “In that day the LORD will take his terrible, swift sword and punish Leviathan . . .”