The United States flag specified by the Flag Act of 1777 had 13 stars.
The act called for 13 alternating red and white stripes and 13 white stars on a blue canton. The number represented the thirteen states that had declared independence from Great Britain and formed the original United States.
The early stars were commonly shown in a circle, a design later associated with the Betsy Ross flag. However, the popular claim that Betsy Ross personally designed the first American flag is not firmly established by contemporary evidence.
The flag changed as new states joined the Union. Congress eventually increased the number of stars while retaining thirteen stripes, so the modern flag has 50 stars but still preserves the original thirteen-stripe pattern.