On June 14, 1777, the Continental Congress adopted the stars and stripes of the American flag. Congress adopted a resolution stating the U.S. flag would adorn 13 alternate stripes of red and white. The Union would be 13 white stars in a blue field, which represented a new Constellation.
The "Stars and Stripes" national flag was based on the "Grand Union" flag, which was a banner carried by the Continental Army in 1776. It also consisted of 13 red and white stripes. Legend has it that Betsy Ross, a Philadelphia seamstress, designed the new canton for the Stars and Stripes flag, which was the circle of 13 stars with the blue background. Some said this was at the request of General George Washington, but historians to this day have not been able to prove or disprove this legend.
As new states were introduced into the U.S. after independence, stars and stripes were added to the flag. But in 1818, Congress enacted a law stating that the 13 original stripes be restored and that only new stars could be joined to represent new states.
Exactly 100 years later, the first Flag Day observance was held on June 14, 1877. Congress instructed that the U.S. flag be flown from all public buildings across the nation. In 1949, Congress deemed June 14 as national Flag Day.