The United States flag has 13 stripes, representing the original 13 colonies. The stripes alternate red and white, while the blue canton represents the union of the states.
The first congressional flag law, the Flag Resolution of June 14, 1777, specified 13 alternating red and white stripes and 13 white stars on a blue field. It did not specify the stars' arrangement, so early flags varied in appearance. The familiar Betsy Ross design is one later interpretation, not a conclusively documented single original pattern.
The flag gained additional stars as new states joined the Union, but Congress kept the 13 stripes permanently. The last change to the stripe count occurred when Vermont and Kentucky joined in 1791; later additions were represented only by stars. This creates a useful distinction: the stripes commemorate the founding colonies, while the stars show the current number of states.