Each state within the Union had its very own unique regimental flags for the period of the Civil War

https://ericksigh824.birchreport.com/posts/exploring-the-history-of-civil-war-flags-a-journey-through-time-4

Each nation inside the Union had its personal unusual regimental flags all the way through the Civil War, reflecting nearby delight and designated histories tied to their participation inside the struggle.