The Union flag, referred to as the Stars and Stripes, symbolized cohesion and patriotism

https://troynvgr831.moderncairn.com/posts/civil-war-flags-in-reenactments-authenticity-and-representation

The Union flag, called the Stars and Stripes, symbolized unity and patriotism, providing 13 stripes and a subject of blue with stars that represented every one nation inside the union.