The Union flag, often known as the Stars and Stripes, symbolized unity and patriotism

https://travismqdt216.zenbloomer.com/posts/embodying-history-the-role-of-civil-war-flags-in-reenactments-2

The Union flag, referred to as the Stars and Stripes, symbolized team spirit and patriotism, presenting thirteen stripes and a discipline of blue with stars that represented every state in the union.