A scattered set of sailors' hospitals became a uniformed corps of officers. John Maynard Woodworth's reforms, the 1889 law creating the Commissioned Corps, the inspections at Ellis and Angel Islands, and the 1902 Biologics Control Act, which made the service the nation's vaccine regulator and seeded the NIH, show a service whose authority was more about screening and standards than command.
Historians debate whether immigrant inspection served genuine disease prevention or nativist exclusion, with harsher treatment of Asian immigrants at Angel Island. Credit for the Commissioned Corps is split between Woodworth's groundwork and the 1889 law.



