Jackson’s Moon

By Erik Nelson

 On May 2, 1863, near a place called Chancellorsville in Spotsylvania County, a near full moon rose shortly after sunset.  A few hours earlier, a Confederate attack led by Stonewall Jackson had come crashing out of the woods near Wilderness Church and rolled up a poorly deployed Union corps. The attack had been stunningly successful, but the assault formations inevitably lost cohesion during an advance of more than two miles. The well-lit landscape, however, provided the Southern command with a rare opportunity to consider pressing the advance into the night.

While line officers hastily regrouped their tired fighting men, Jackson used the favorable visibility to ride forward and reconnoiter. He knew the Union army was also rallying and wanted to strike before it could consolidate a new position. During this pause in the fighting, the Southern foot soldiers were not aware their commander had gone ahead to scout the terrain. When a group of horsemen approached from where the Yankees were, backlit by the bright moon, the Southern infantry opened fire.

Captain Francis A. Donaldson was a Union soldier at Chancellorsville and described the night Jackson was shot as follows: “The night was a glorious one, the full moon shining brightly and making objects quite distinct in the surrounding woods. An occasional cloud would now and then obscure it, only to make its rays more brilliant as they again burst forth and illuminated the forest.”[i]

Historians writing of that spring battle have not consistently made clear the atmospheric conditions during the period when Jackson’s flank attack lost momentum. James I. Robertson’s biography of Stonewall Jackson (1997) for example, presents seemingly conflicting statements. The author notes how on the night of May 2, 1863, “the full moon, unencumbered by clouds, bathed the Wilderness in a silvery light (p. 726).” On the preceding page, however, he writes that “it was dark when Lane reached the Plank Road (p.725).” On the next page, he recounts that “sounds became audible some 200-300 yards in the pitch-blackness ahead (p. 727).” The “pitch-blackness ahead” could have meant the shadows cast by the moon, but the author does not say that.[ii]

In 1996, Blue and Gray Magazine published an article detailing the exact time of sunset and moonrise that day at Chancellorsville.  Donald W. Olson and Russell L. Doescher, professors at Southwest Texas State University, had developed a program that calculated atmospheric conditions on specific dates in the past and they revealed that the conditions on May 2, 1996, were going to replicate those of May 2, 1863.  The National Park Service invited visitors to the Chancellorsville battlefield that evening, to see what those conditions looked like on the ground. Nearly 200 people availed themselves of that unusual opportunity.

Near the site where Jackson was shot, the moon came up 41 minutes before sunset on May 2, 1996, just one minute earlier than it had on the day of Jackson’s flank attack. On both days, the moon’s face was 99 percent full. That night in 1996 revealed just how bright the woods west of Chancellorsville had been when Jackson rode toward the Federal lines. The experience became perhaps the closest someone could get to a precise Civil War moment.

Jackson surely realized that the moonlit landscape made it feasible for Southern troops to press forward after sundown. George Washington once wrote that “favorable moments, in love as in war, once lost, are seldom regained.” The bright night appears to have beckoned to the aggressive Jackson as his favorable moment, to be seized and exploited. What might have been, however, got cut short by a volley of musketry.

[i] Franics A. Donaldson, Inside the Army of the Potomac: The Civil War Experience of Captain Francis A. Donaldson, ed. I Gregory Acken (Mechanicsburg: Stackpole Books, 1998), p. 241.

[ii] James I. Robertson, Jr., Stonewall Jackson: The Man, The Soldier, The Legend (Simon & Shuster MacMillan: New York, 1997).

Note: Sun and moon data for specific days and places in the past is now readily available from the Naval Observatory. A website at https://aa.usno.navy.mil/data/RS_OneDay can be accessed to find atmospheric conditions for any day and place between 1700 and 2100.