He wrote the poem in the correct meter to fit the popular English song " Anacreon in Heaven." On their way back to Baltimore, Key showed the poem to Skinner, who is probably the person who eventually passed it along to a young printer's assistant named Samuel Sands, who typeset and printed the poem just a few days later. The next morning, on September 14th, Key was inspired to write the poem "Defence of Fort McHenry" when he saw the American flag still flying over Fort McHenry. They witnessed the battle from the deck of their American truce ship. Their ship was tethered to a British ship to prevent them from returning to Baltimore due to the information they had gathered during the negotiation. Key, Skinner, and Barnes were then transferred to the HMS Surprise and then to their own ship on September 13th. Many days of negotiation eventually led to Barnes' release. Key and Skinner arrived in the Chesapeake Bay on an American truce ship and boarded the HMS Tonnant, commanded by Admiral Alexander Cochrane. William Beanes, an American physician arrested as a spy. Key witnessed the battle after he and John Stuart Skinner, a lawyer, publisher, and prisoner of war exchange officer, had been permitted by President James Madison to negotiate the freedom of Dr. On September 14, 1814, after witnessing the failed bombardment of Fort McHenry by the British, Francis Scott Key, a Georgetown lawyer and poet, wrote the contrafactum song, " Defence of Fort McHenry," a four stanza poem to be sung to the popular tune " Anacreon in Heaven" by English composer John Stafford Smith which would later be known as the Star-Spangled Banner. Library of Congress Prints & Photographs Division.