Flags had been repeatedly used as rallying points for the time of battles; infantrymen could gather around their colors for morale
https://troynfmn638.huicopper.com/local-shops-and-online-stores-where-to-buy-civil-war-flags-today
Flags have been normally used as rallying features in the course of battles; soldiers would assemble round their colorings for morale give a boost to when confronted with overwhelming odds.