Washington, D.C. (JFK+50) Flag Day was established by a proclamation signed by President Woodrow Wilson on May 30,1916, but National Flag Day was established by the Congress of the United States and the law was signed by President Harry S Truman on August 3, 1949.
The Continental Congress adopted the Flag of the United States on June 14, 1777 by stipulating that...
"the flag of the United States shall be 13 alternate stripes red and white" and"that the Union be 13 stars, white in a blue field, representing a new Constellation."
According to www.usflag.org/, however, it was B. J. Cigrand, a teacher in Wisconsin, who originated the idea for Flag Day by arranging for the students in his public school district to observe June 14, 1885 as 'Flag Birthday.'
Eventually, Mr. Cigrand and Leroy Van Horn organized the American Flag Day Association which sponsored the first general public school celebration of Flag Day in Chicago on June 14, 1894. It was an event in which 300,000 students participated.
In 1961, President Kennedy issued a proclamation directing that the flag of the United States be "displayed on all government buildings on (Flag Day) June 14, 1961."
The proclamation reads....
"The American flag is emblematic of a Nation indivisible although its people are of diverse ethnic strains, races and religions; and
Our flag symbolizes the ideals of freedom, justice and brotherhood which are deeply rooted in our political and spiritual traditions and which have helped our country become a land of progress and a rampart of liberty; and
In combat our flag has always been a guide and inspiration to our armed forces...".
"The History of Flag Day," www.usflag.org/
Flag Day Poster