The Union flag, called the Stars and Stripes, symbolized harmony and patriotism

https://arthurjbzo517.ironwoodscope.com/posts/a-closer-look-at-historic-civil-war-flags-what-they-represent-2

The Union flag, is called the Stars and Stripes, symbolized team spirit and patriotism, providing 13 stripes and a container of blue with stars that represented each one nation inside the union.