In 1777 on June 14th, the Second Continental Congress adopted an official flag for their new country. We in the United States also celebrate the birth of the US Army on this day - that same congress had reached consensus on the army two years earlier.
Flag Day isn't one of the most well-known holidays, but in my family we always paid attention. Not so much for the flag part; more because it happens to be my Mom's birthday. Very fitting that she was born on a day with such historical importance, given how much she loves the subject of history.
So happy birthday to my Mom, the US Army, and the official adoption of the US flag. Many happy returns to all three!