While making the pattern for the first American flag, Betsy Ross was reportedly able to create a 5-pointed star from a single sheet of paper with one cut.

June 14 is Flag Day, commemorating the adoption of the US flag by the Continental Congress in 1777.

The first US flag had 13 stars, while the second had 15 stars. Since states sometimes entered the union in groups, no US flags had 14, 16, 17, 18, 19, 22, 39, 40, 41, 42, or 47 stars.

New US flags can be introduced only on the Fourth of July.

The "star-spangled banner" described in the US national anthem is the flag with 15 stars and 15 stripes.

The state flag for Hawaii is the only state flag that includes the flag of a foreign country.

Not all state flags are rectangular.