Yes I noticed that.

Here are commands from Casey's Infantry Tactics, 1862.

http://www.usregulars.com/csb16.html

note:

"A battalion, in square, will never use any other than the fire by file and by rank; the color being in the line of file closers, its guard will not fall back as prescribed No. 41; it will fire like the men of the company of which it forms a part.

960. If the square be formed in four ranks, the first two ranks will alone execute the firings prescribed above; the other two ranks will remain either at shoulder or support arms 961."

From...

http://www.usregulars.com/library.htm

_________________
David Upton