The attack on Baltimore did not come from nowhere. Three weeks earlier, on August 24, 1814, a force of 4,500 seasoned British troops under Major General Robert Ross had marched into Washington, D.C., and set fire to the White House, the Capitol, and other government buildings. President James Madison and the entire federal government had fled to Brookeville, Maryland. The nation's capital lay in ruins. The British had been emboldened by Napoleon's defeat in Europe, which freed thousands of veteran soldiers for deployment to North America. Vice-Admiral Alexander Cochrane saw Baltimore as the next logical target -- the nation's third-largest city, a thriving port, and the home base of the privateers who had been raiding British merchant ships. A combined land and sea assault would crush American morale for good.

Baltimore was ready. Major General Samuel Smith of the Maryland Militia had spent weeks strengthening the city's defenses, and when 5,000 British troops splashed ashore at North Point on September 12, he sent General John Stricker with 3,000 men to delay their advance. The gambit worked better than anyone expected. During the opening skirmish, an American sharpshooter -- either Daniel Wells or Henry McComas of Captain Aisquith's rifle company, both of whom were killed moments later -- shot and killed General Ross himself. Command fell to Colonel Arthur Brooke, who pushed the Americans back but lost precious time. By the time the British reached the outskirts of Baltimore, they found Hampstead Hill bristling with 100 cannons and more than 10,000 troops dug in behind a mile-wide arc of earthworks stretching from Canton to Belair Road. The defenses were far stronger than anything the British had anticipated.

While Brooke stalled on land, Cochrane launched the naval assault. Starting on the morning of September 13, British warships bombarded Fort McHenry for 25 hours straight with mortar shells and Congreve rockets. The star-shaped fort, commanded by Major George Armistead, absorbed the punishment. A nighttime landing party tried to slip past the fort in small boats to outflank the defenders, but the attempt failed. At 3:00 a.m. on September 14, Brooke ordered his troops back to the ships. He had been instructed not to attack unless the fort held fewer than 2,000 defenders -- the fortification clearly held far more. When the oversized garrison flag went up at reveille that morning, replacing the smaller storm flag that had flown through the battle, the message was unmistakable. Baltimore would not fall.

Key had watched it all from the deck of a British truce vessel. He was there on a mercy mission, carrying letters from wounded British officers who praised the medical care given them by Dr. William Beanes, an American civilian prisoner. The British agreed to release Beanes but refused to let either man go until the assault was finished. So Key stood through the night, straining to see through smoke and rain whether the fort still held. His poem, originally titled "Defence of Fort M'Henry," was printed as a pamphlet by the Baltimore American newspaper. It was soon set to the melody of "To Anacreon in Heaven," a popular British drinking song. The combination spread across the country. In 1931, Congress made it the national anthem.

Colonel Brooke withdrew his army. Cochrane's fleet sailed south to regroup before its final, and equally unsuccessful, assault at the Battle of New Orleans. Major Armistead was promoted to lieutenant colonel but died just three years later at 38, his health broken by the arduous preparations for the battle. Fort McHenry stands today as a National Monument and Historic Shrine, its star-shaped walls still overlooking the Patapsco. The original flag -- Pickersgill's enormous creation -- is preserved at the Smithsonian's National Museum of American History, its fabric thinned by age but still bearing the fifteen stars and fifteen stripes that Key saw through the clearing smoke. Maryland still celebrates Defenders Day each September 12, and the lineage of the 5th Maryland Infantry Regiment that fought at North Point lives on in the Maryland Army National Guard's 175th Infantry Regiment.