The 1777 Flag Resolution specified 13 stars for the first official congressional design of the United States flag.
On June 14, 1777, the Continental Congress resolved that the flag should have thirteen alternating red and white stripes and thirteen white stars in a blue field. The stars represented the thirteen United States, while the resolution described them as a “new constellation.” The anniversary of that action is now observed as Flag Day.
The resolution did not prescribe a particular arrangement for the stars. Early makers used circles, rows, and other patterns, which is why several different thirteen-star flags are historically plausible. The familiar Betsy Ross design, with stars in a circle, is associated with the period but is not conclusively documented as her personal creation.
The current flag still has thirteen stripes, but it has 50 stars, one for each state. Congress increased the number of stars as states joined the Union; the stripes returned to thirteen in 1818 after a brief fifteen-stripe design.