Why do we celebrate flag day?

It is observed for us to remember the Civil war and to show the Americans symbol. WRONG!

Flag Day is celebrated in June 14th in recognition of the date that the Continental Congress passed the flag resloution - June 14th 1777: Resolved: that the flag of the United States be made of thirteen stripes, alternate red and white; that the union be thirteen stars, white in a blue field, representing a new Constellation.