In 1916, President Woodrow Wilson issued a proclamation that officially established June 14 as Flag Day; in August 1949, National Flag Day was established by an Act of Congress. Flag Day is not an official federal holiday. Title 36 of the United States Code, Subtitle I, Part A, CHAPTER 1, § 110 is the official statute on Flag Day; however, it is at the President's discretion to officially proclaim the observance.
On June 14, 1937, Pennsylvania became the first U.S. state to celebrate Flag Day as a state holiday, beginning in the town of Rennerdale. New York Statutes designate the second Sunday in June as Flag Day, a state holiday.
Perhaps the oldest continuing Flag Day parade is in Fairfield, Washington. Beginning in 1909 or 1910, Fairfield has held a parade every year since, with the possible exception of 1918, and celebrated the "Centennial" parade in 2010, along with some other commemorative events.
Appleton, Wisconsin claims to be the oldest National Flag Day parade in the nation, held annually since 1950 It was also named "Most Patriotic City in America" by AmericaTheBeautiful.com in 2008.
Quincy, Massachusetts has had an annual Flag Day parade since 1952 and claims it "is the longest-running parade of its kind in the nation." The largest Flag Day parade is held annually in Troy, New York, which bases its parade on the Quincy parade and typically draws 50,000 spectators. In addition, the Three Oaks, Michigan Flag Day Parade is held annually on the weekend of Flag Day and is a three-day event and they claim to have the largest flag day parade in the nation as well as the oldest.