I gave it my best shot. I found many cases of Union troops using it. I found cases where Union troops in Virginia used it. I found cases where Confederates used it but not in Virginia, not by Jackson or by Lee.

It seems to have been a common field manuver. One officer described being caught in an open field with enemy cavalry lirking in the woods, formed his unit into square, and advanced. When he felt safe enough from the cavarly threat, he quickly formed his unit back into line. He made it sound as if they did it all the time.

David