The British began bombarding Fort McHenry early in the morning on September 13, 1814. The three prisoners, Key, Skinner, and Beanes waited apprehensively for a conclusion to the battle. They knew that Fort McHenry had not surrendered as long as the shelling continued. Then suddenly after twenty-five agonizing hours there was silence. The battle was over, and the British had abandoned their attack on Baltimore.
In the predawn darkness, the prisoners searched for a sign that the American forces had won the day. The American flag, which was commissioned in 1813 to “be so big that the British would have no trouble seeing it from a distance,” was still flying over Fort McHenry. Key was so moved by the sight of the majestic flag snapping in the breeze that he penned a few lines of a poem on the back of a letter he carried in his pocket. First published as "Defense of Fort McHenry," Key’s famous poem would be put to music and become the national anthem of the United States in 1931 as, “The Star-Spangled Banner.” The verses Key composed captured for the nation not only a triumphant moment when a flag withstood the rigors of battle but also symbolized the triumph and pride of a young nation. The American flag continued to represent this patriotic pride for the citizens and military personal as the United States evolved.