O say, can you see  

The first celebration of the U.S. Flag birthday was held in 1877 on the 100th anniversary of the Flag Resolution of 1777.  

However, it is believed that the first annual recognition of the flag’s birthday dates back to 1885 when school teacher, B.J. Cigrand, first organized a group of Wisconsin school children to observe June 14 — the 108th anniversary of the official adoption of The Stars and Stripes. – U.S. Department of Defense