The annual holiday celebrates the history and symbolism of the American flag, according to the Old Farmer’s Almanac. https://www.almanac.com/content/flag-day-celebration-american-flag#
The Stars and Stripes was adopted as the official American flag June 14, 1777 during the Revolutionary War. Colonial troops were fighting under many flags with various symbols and slogans. There were 13 white stars on a blue field and 13 alternating red and white stripes on the first official national flag. The modern flag has 50 stars for each state in the union with the 13 stripes remaining.
A year after the Stars and Stripes flag was adopted, Flag Day was first celebrated in 1877 and continues today. It is not a federal holiday but the colors are to be flown at all government buildings.
There is no proof that Betsy Ross designed and sewed the first flag although she did make ensigns and pennants for the Philadelphia navy during the war.
