What did Francis Scott Key's poem "The Star Spangled Banner" contribute to the American flag?

Francis Scott Key's poem "The Star-Spangled Banner," written in response to the defense of Fort McHenry during the War of 1812, significantly contributed to the symbolism of the American flag. The poem vividly describes the flag as a symbol of resilience and national pride, particularly in the face of adversity. As it captures the moments of battle and the sight of the American flag still waving at dawn, it elevates the flag from a mere piece of fabric to a powerful emblem representing the nation's values, struggles, and indomitable spirit. This transformation made the flag synonymous with American identity, unity, and patriotism, which is why it is considered a symbol of America. The national song aspect comes later, as it is officially recognized as the national anthem, but its contribution as a symbol is foundational to how Americans understand and honor their flag today.