Final answer:
The Star-Spangled Banner was officially recognized as the U.S. national anthem in 1931, previously being the poem 'In Defense of Fort McHenry' written by Francis Scott Key in 1814.
Step-by-step explanation:
The song 'The Star-Spangled Banner' was officially adopted as the national anthem of the United States on March 3, 1931 through a congressional resolution. This song has a rich history, being the poem 'In Defense of Fort McHenry', as penned by Francis Scott Key in 1814. Key was inspired to write this poem after witnessing the British bombardment of Fort McHenry during the War of 1812, and being moved by the sight of the American flag withstanding the attack, thus symbolizing a resilient United States.
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