Today we celebrate the acceptance of our country’s national flag. It was first adopted as the ‘unified colonial fighting flag’ in June 1775 but became our country’s symbol June 14, 1777. You can learn more here –

14 Fun Facts About the U. S. Flag (15-Minute Books Book 1518)
Star-Spangled: The Story of a Flag, a Battle, and the American Anthem
Our Flag
The American Flag: A Handbook of History & Etiquette (Books of American Wisdom)
Sons of the Flag
Long May She Wave: A Graphic History of the American Flag
Inventing the American Flag: How the Stars and Stripes Was Woven from Symbols