The Union flag, is called the Stars and Stripes, symbolized unity and patriotism

https://zionscfs876.pinehavenscope.com/posts/a-collector-s-dream-the-fascinating-world-of-civil-war-flags

The Union flag, generally known as the Stars and Stripes, symbolized unity and patriotism, providing 13 stripes and a field of blue with stars that represented every nation within the union.