"Battle Hymn of the Republic" has more than one setting within its lyrics, but its historical setting may be the most important.
Most narrowly, but perhaps most usefully, the song can be set within the specific conditions of the United States in November 1861, the month in which Julia Ward Howe wrote the song. Following the secession of South Carolina in December 1860, another ten states left the Union by May 1861. Newly elected President Abraham Lincoln refused to acknowledge their claim that secession was a right of the states, and he took military steps to hold federal outposts and enforce federal laws in the rebelling territories.
In July 1861, the armies of the Union and the newly formed Confederate States of America met on a battlefield in Virginia, just 25 miles from Washington, D.C. Prior to this battle, Northern political and military leaders anticipated a short war, but the poor performance of the Union troops and the surprising resilience of the Southern soldiers convinced Northern leaders and the general public that the war would be long and bloody.
In November of 1861, when Julia Ward Howe visited Washington, D.C., and saw the troops training, she and other supporters of the cause were preparing for this long battle. No longer expecting a simple, painless victory, they needed to frame the war and its anticipated sacrifices in more suitable terms. Howe's song was an attempt to do just that.
While the political and military conditions of late 1861 provide "Battle Hymn of the Republic's" most immediate setting, the song can also be set within the ancient Christian belief in the Second Coming of Jesus.
When Howe writes, "Mine eyes have seen the glory of the coming of the Lord," she places her 1861 call to battle within the context of a much older summons to service on behalf of God's work on earth in preparation for the end of time. Christians have held this belief in the Second Coming for 2000 years. But during the 19th century, many American Christians concluded that this epic event would occur during their lifetimes.
Belief that the Second Coming and inauguration of the millennium—a 1000-year period of perfect temporal peace and prosperity—was at hand, was a defining feature of American evangelicalism in the decades preceding the Civil War. Howe's excited declaration that she has "seen the glory of the coming of the Lord" resonated with Americans who shared this millennial vision.
Hang out on a street corner with a cardboard sign telling people you've seen God: crazy. Write it down in a military hymn: remembered forever.