The symbol of freedom in the national anthem is the American Flag. When in 1814, Francis Scott Key penned the poem that would become the National Anthem, he was being held captive by the British during the War of 1812. Where he was kept he could see the battle raging at the nearby Ft. McHenry and the American flag was flying. All through the night he watched on at the “rockets red glare,” and “the bombs bursting in air.” Which illuminated the flag, showing that the British had not defeated the American forces. I hope this helps!