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

https://deanmwsm217.wordcanopy.com/posts/flags-as-historical-artifacts-insights-into-the-civil-war-era-2

The Union flag, is named the Stars and Stripes, symbolized solidarity and patriotism, featuring 13 stripes and a area of blue with stars that represented every one nation in the union.