Here we have 2 gifs. The first is 1,000 frames long and does not loop. The second was created later with the flag at half the dimensions, 200 frames, and loops. They show all 27 changes in the official US flag to date from June 14, 1777, when the flag was first adopted, to the present. The first was too large for photobucket, so it's on deviant art. The second, though, is small enough for photobucket to host.
Look up the official historic flags if you want to know more information.
All flags included in those gifs never go out of date and are legal to be flown at any time.
