Which design element has changed the most in the history of the American flag?

The arrangement of stars has changed the most in the history of the American flag because it directly reflects the admission of new states into the Union. As the country expanded, the flag has been updated multiple times to include new stars representing each state. The most notable adjustments occurred in 1777, when the original 13 stars were created for the 13 colonies, followed by several updates over the years, leading up to the current design with 50 stars for the 50 states.

While the number of stripes and the colors used have remained relatively constant over the years—with the flag retaining 13 stripes representing the original colonies, and the colors red, white, and blue symbolizing certain values—these elements did not experience the same frequency of change as the star arrangement. The size of the flag has varied based on purpose and context, but this is not a fundamental design change like the evolving arrangement of stars. Therefore, focusing on the stars provides the best insight into the adaptive nature of the American flag in response to the country's growth and unity.