Flags were generally used as rallying issues for the period of battles; soldiers could gather around their colours for morale

https://manuelfggs448.meridiannest.com/posts/flags-of-honor-the-symbolism-behind-civil-war-colors-and-emblems

Flags have been every so often used as rallying factors in the time of battles; squaddies may bring together round their colorations for morale improve when confronted with overwhelming odds.