The United States adopted the Flag Act creating its first official national flag in 1777.
The Second Continental Congress passed the Flag Resolution on June 14, 1777. It specified thirteen alternating red and white stripes and a blue field containing thirteen white stars. The thirteen symbols represented the thirteen states that had declared independence and formed the new union.
The resolution did not specify the stars' arrangement, their exact shape, or a precise design process. That uncertainty is why the popular story that Betsy Ross personally designed the first flag cannot be established as fact from surviving contemporary evidence. June 14 later became Flag Day, but it is separate from Independence Day on July 4.