New York Marine Hospital, known as the Quarantine, was New York City's first line of defense against immigrant borne infectious diseases like smallpox, cholera, typhus and yellow fever. Health inspectors met ships in the harbor. If they found a sick passenger or crewman, they would flag the vessel with a dreaded Yellow Jack and divert everyone on board to the Quarantine until they were cleared as disease free. On September 2, 1858, in an act of anarchy, arsonists had set fire to the Quarantine. The walled complex of about 20 buildings stood in Tompkinsville, Staten Island, south of today's ferry docks. No one died in the fires, but ringleaders Thompson and Tompkins went on trial for arson just two weeks later. Judge Henry Metcalfe acquitted both men, which wasn't a surprise. He lived near the Quarantine and had publicly opposed it for years after a relative contracted yellow fever. After the trial, the Quarantine was relocated offshore to a floating hospital, the Florence Nightengale. In 1866, it was moved to two islands, Swinburne and Hoffman, created from landfill off South Beach, Staten Island. Decades later, the facility moved to Ellis Island.