The Continental Congress adopted the first United States flag on June 14, 1777.
The Flag Resolution stated that the flag would have 13 alternating red and white stripes and 13 white stars on a blue field. The stars represented the 13 states, while the stripes recalled the united colonies.
The resolution did not specify the arrangement of the stars, so early flags used several patterns. The familiar circle of stars became associated with the so-called Betsy Ross flag, although historians have not established that Ross designed the first flag.
The number of stars and stripes changed as new states joined the Union. In 1818, Congress fixed the design at 13 stripes and one star for each state, creating the basic structure of the modern flag. Flag Day is observed annually on June 14.