The U.S. flag was first authorized by Congress on June 14, 1777. The flag is the third oldest in the world, even older than the Union Jack used in the United Kingdom. The flag was first flown on August 3, 1777, atop Fort Stanwix in New York.
The red on the flag symbolizes valor and zeal, the white symbolizes hope and purity and the blue symbolizes loyalty, sincerity and justice. The flag received the nickname "Old Glory" in 1831 from Captain William Driver. For some time following the admission of Kentucky and Vermont into the Union, the flag had 15 stripes. Over a 50-year period in the early to mid 1800s, 17 different official versions of the flag existed, largely due to the rapid expansion of states.