How many stripes are on the United States flag?

The United States flag features a total of 13 horizontal stripes. These stripes symbolize the original 13 colonies that declared independence from Great Britain in 1776. The stripes alternate in red and white, with seven red stripes and six white stripes. This design serves to honor America's historical roots and the unity of the original states.

In contrast, the other options do not reflect the flag's design. There were 10, 12, or 15 stripes at no point in the flag's history. The 13 stripes have remained a fundamental aspect of the flag's design since the early 19th century, representing the enduring legacy of the founding colonies. Thus, the answer reflects both a historical significance and a direct representation of the United States' origins.