The current United States flag has 13 stripes, representing the thirteen colonies that declared independence from Great Britain.
The stripes alternate red and white across the flag. Their symbolism comes from the Flag Resolution adopted by the Continental Congress on June 14, 1777. That resolution specified thirteen stripes and thirteen white stars on a blue field, describing them as representing a new constellation.
The flag changed as new states joined the Union. From 1795 to 1818, it had 15 stars and 15 stripes to reflect Vermont and Kentucky. Congress later returned the number of stripes to 13 while continuing to add stars for new states.
The present design has 50 stars, one for each state, but it retains the original 13 stripes. The last star was added for Hawaii in 1960. Flag Day is observed annually on June 14, the anniversary of the 1777 resolution.