A century ago, in the shadow of the Statue of Liberty, one of the world's greatest public hospitals was built. Massive and modern, the hospital's twenty-two state-of-the-art buildings were crammed onto two small islands, man-made from the rock and dirt excavated during the building of the New York subway. As America's first line of defense against immigrant-borne disease, the hospital was where the germs of the world converged. The Ellis Island hospital was at once welcoming and foreboding—a fateful crossroad for hundreds of thousands of hopeful immigrants. Those nursed to health were allowed entry to America. Those deemed feeble of body or mind were deported. Three short decades after it opened, the Ellis Island hospital was all but abandoned. As America after World War I began shutting its border to all but a favored few, the hospital fell into disuse and decay, its medical wards left open only to the salt air of the New York Harbor.