The 13 stripes on the United States flag represent the 13 original colonies.
The stripes alternate red and white and symbolize the colonies that declared independence from Great Britain during the American Revolution. The design preserves the number of founding colonies even though the United States later expanded to 50 states.
The Continental Congress approved the first official Stars and Stripes design through the Flag Resolution of June 14, 1777. That resolution specified 13 alternating stripes and 13 white stars on a blue field. The wording described the stars as representing a “new constellation.”
A common mix-up is assuming that the stripes represent the current number of states. Stars, not stripes, change when states join the Union. Congress reduced the number of stripes back to 13 in 1818 after briefly increasing both stars and stripes to 15 for Vermont and Kentucky. The current flag has 50 stars and 13 stripes.