The flag of the United States consists of 13 alternating red and white stripes and a blue canton containing white stars. The 13 red and white stripes represent the original 13 colonies that became the first states in the United States of America in 1776.
The first official national flag was formally approved in a resolution on June 14, 1777; regarding the flag’s stripes, it specified “thirteen stripes, alternate red and white.” The number of stripes changed in 1795, after the Flag Act of 1794 mandated that there be 15 stripes; this was after the admittance of two new states in recent years. The Flag Act of 1818 reverted the number of stripes back to 13. This act also mandated that going forward, the number of stripes on the flag should be kept at 13.