A full moon hung bright in the sky the night General "Stonewall" Jackson died.  A new theory posits that the moon may be responsible for the Civil War general's death. The tide turned in the Civil War in part because Jackson's own men inadvertently shot him at the battle of Chancellorsville in Virginia in May 1863.

The Southern Civil War general was battling encroaching Union troops in northern Virginia. And, although Lieutenant General Thomas J. "Stonewall" Jackson and General Robert E. Lee were outnumbered, the momentum prior to that had been on their side. Jackson's death left the Confederate army missing one of its most intelligent strategists- and only two months later, the decisive Battle of Gettysburg occurred, leaving massive Confederate losses and essentially handing the victory to the Union.

Astronomer Don Olson and researcher Laurie E. Jasinski from Texas State University say that when Jackson's men fired on him, they couldn't see him because of the silver-white moonlight. His troops from the 18th North Carolina Infantry Regiment may not have known their opponent was also their General.

"The Moon was shining very brightly, rendering all objects in our immediate vicinity distinct...," one account by a confederate captain reads, "The Moon poured a flood of light upon the wide, open turnpike."

Jackson and his troops had had a very successful day, and he'd kept his men fighting long into the night, which was unusual. He went on a scouting mission to see if they could cut off the Union troops and, on his return, was shot by his own party. Mistaking Jackson for advancing Union soldiers, Major John Barry ordered his troops to fire.

Olson and Jasinski calculated out exactly where Jackson's party and the 18th North Carolina regiment would have been at the time of the shooting, around 9 p.m, using battle maps by military historian Robert Krick and almanacs. Then they calculated the lunar phase and moon's position with the help of astronomical software.

"Once we calculated the compass direction of the moon and compared that to the detailed battle maps published by Robert Krick, it quickly became obvious how Stonewall Jackson would have been seen as a dark silhouette, from the point of view of the 18th North Carolina regiment," Olson said.

"The 18th North Carolina was looking to the southeast, directly toward the rising moon," they said. The full moon hung at "25 degrees above the horizon" at the time- exactly the wrong angle.

Olson said "The bright moon would've silhouetted Jackson and his officers, completely obscuring their identities. Our astronomical analysis partially absolves the 18th North Carolina from blame for the wounding of Jackson," Olson says.

In other words, a trick of the moon may be responsible for Stonewall Jackson's death - and thus the end of the Civil War, the molding of the nation, and "the proposition that all men are created equal", as Lincoln put it during the Gettysburg Address.