Just as you pass under Key Bridge you’ll find a red, white, and blue nun buoy, again to starboard. It is the only Coast Guard buoy in the entire country that does not conform to the standard buoyage system. It marks the spot where Francis Scott Key was being held prisoner on the British flagship, HMS Tonnant, and from where he viewed the bombardment of Fort McHenry. To the left of the buoy, you can see the buildings of mid-town Baltimore. At their base, and in the foreground by about two and a half miles is a grassy hill that is Fort McHenry. Minus the skyscrapers, this is the view that Key would have had of the fort during the naval siege.
Key was a young attorney in Georgetown. As the British prepared to march on Baltimore, they took an elderly town doctor, Dr. William Beanes prisoner. People in town feared Beanes might be hanged and approached Key to petition the British for Beanes’ release on the basis that he had been instrumental in providing medical care for injured British soldiers. Key asked for the help of Col. John Skinner, an American agent for prisoner exchange. On the morning of 3 September, 1814, Key and Skinner sailed to the flagship under a flag of truce. Adm. Cochrane, however, felt they had seen too much of their preparations, and held them on board. Ten days later, at 0700 on 13 September, the bombardment began and continued for 25 hours, during which 1,500 exploding bombshells of up to 220 pounds each and countless rockets, rained down on the fort. Keys, Skinner, and Beanes watched through the night with grave concern, but with the first morning light, they could still see the 30 by 42 foot battle flag still flying over the fort. Keys was only an amateur poet, but he began to pen a poem on the back of a letter, and finished it later in his hotel room and titled it “Defence of Fort M‘Henry.” In October, a Baltimore actor sang the resulting song in a public performance for the first time, and retitled it The Star-Spangled Banner.
This is a related video I think you'll find both interesting and inspiring. Keep in mind that a large part of the success in defending Fort McHenry also came from their sinking 22 ships in the channel so the British fleet couldn't close with the fort at close range. The fort sits right on the point, making it possible to close from three sides. Had the British been able to fire point blank, the outcome may have been much different.
From there Thistle sailed into Curtis Creek to the Coast Guard Base, then back down the Patapsco. We entered Stony Creek in a light drizzle, passed the bascule bridge during its last opening of the day, turned into Nabbs Creeks, and dropped anchor in Back Cove for the night.