The flag has been modified 27 times since its inception, with the current 50-star design being the longest-used version.
The current design was created by 17-year-old Robert G. Heft as a school project. He received a B- but got it changed to an A after Congress adopted his design.
There are specific rules for flag etiquette outlined in the U.S. Flag Code, including that it should never touch the ground.
The flag should be displayed from sunrise to sunset, but can be displayed 24 hours if properly illuminated at night.
Six American flags have been planted on the moon by Apollo missions, though they've likely been bleached white by solar radiation.
The largest American flag in the world is called the "Superflag" and measures 505 feet by 255 feet, weighing 3,000 pounds.