In 1949, President Truman signed an Act of Congress designating June 14th of each year as National Flag Day. That's today!
Here's a short video on the history of the American flag. It was produced in 1938, 20 years prior to the last two states being admitted to the union, and just prior to the start of World War II.
If you're feeling patriotic now, how about a chorus of "You're a Grand Old Flag"? It can be found on the CD Stars and Stripes Forever, Volume II [CD MISCELLANEOUS STA].