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

https://simonadmb548.valiantfield.com/posts/a-closer-look-at-historic-civil-war-flags-what-they-represent-2

The Union flag, called the Stars and Stripes, symbolized team spirit and patriotism, proposing thirteen stripes and a container of blue with stars that represented each country within the union.