On June 18, 1812, the United States declared war on England, then the greatest power on earth, to preserve "Free Trade and Sailors' Rights." The British, while at war with France, had interfered with U.S. trade and had boarded American ships to force sailors into service on their ships. It was not until 1814, after England had defeated Napoleon, that the British would test a stubborn, determined people in Baltimore, an anti-British hotbed. To attack the city successfully, the British would first have to seize Fort McHenry, the key to the city's defense. Late summer 1814 was a critical time for the United States during the War of 1812. A British blockade was taking effect and trade was critically diminished. Some segments of the country, particularly New England, proposed striking a separate peace accord with the British, who were looking for opportunities to inflict a major morale blow to the Americans. That would bring a speedy end to the war in England's favor. Baltimore, Maryland appeared to be the most likely target. The city had openly proclaimed its anti-British stance days after war was declared. An angry mob destroyed the building where a Federalist newspaper criticized America for going to war. Baltimoreans also struck at the British directly. Swiftly sailing schooners seized British merchant ships and transported limited cargoes to foreign ports. Other cities followed the practice; however, Baltimore alone accounted for about 30 percent of all British merchant ships captured by the U.S. during the war. From this, Baltimore earned the nickname "nest of pirates." The blockade resulted in stockpiles of goods along the city's wharves. Shipbuilders avoided bankruptcy by building blockade runners and vessels for the U.S. Navy. The potential to strike a decisive morale blow, capture goods, a frigate, and settle a score, may have influenced the British decision to attack Baltimore. The city fathers foresaw a possible attack on the harbor, so preparations were made as early as 1813. A committee of public supply was established to raise funds for various construction projects. Citizens began to dig a huge entrenchment along the outskirts of the city, facing east. Large gun barges were constructed to defend the harbor. The city militia was called on for periodic drills. The regular army also assisted. Colonel Joseph G. Swift dispatched Captain Samuel Babcock to supervise improvements at Fort McHenry. Improvements included mounting a battery of 32-pound cannons along the water's edge, construction of hot shot furnaces, fortifications at Lazaretto Point, and additional gun batteries along the Patapsco River. On the morning of September 12, 1814, the British landed more than 3,000 troops at North Point. They marched north and west to attack the city. That night, after the Battle of North Point, they reached Hampstead Hill, where 12,000 Americans blocked their path. The British troops waited for the navy to subdue Fort McHenry and sail into the harbor to shell the city. At first light on September 13, British ships of war began to fire bombs, rockets, and cannon balls at Fort McHenry. The hope was the Americans would panic, evacuate the fort and leave Baltimore defenseless. For 25 hours, as lightning flashed and rain fell, the British bombarded the fort, firing between 1,500 and 1,800 rounds, but causing only four deaths and leaving 24 wounded. Major George Armistead and the 1,000 patriot defenders fired back with their cannons when the British ships sailed within range. Realizing the attack had failed, the British sailed downriver to North Point to retrieve their retreating soldiers. The Battle of Baltimore was over. It was the most dangerous period following the War for Independence as patriots faced and defeated a vengeful foreign power on American shores. The War of 1812 has been called the "second War of Independence," because it forged national character and demonstrated that Americans would unite not only to win liberty, but to keep it. After the battle, the young flag, with 15 stars and broad stripes, waved in defiance. The courage Francis Scott Key witnessed inspired him to write the words sung today as the National Anthem. Fort McHenry, home of the "Star-Spangled Banner," still flies the 15-star flag every hour of every day, above its ramparts.