From 1920 to 1924 he was a consultant and investigator with the United States Public Health Service. In 1924 he went with the fish farmer Fred J. Foster on an expedition to Central America. From 1925 to 1931 he was again director of the U.S. Fisheries Biological Station, Beaufort, North Carolina. From 1931 to 1949 he worked as a senior ichthyologist at the Bureau of Fisheries. In 1935 and 1937 he made two further collecting expeditions to Panama. In 1949 the United States Department of the Interior posthumously honored him with its Distinguished Service Award.
Hildebrand's research focused on the life of turtles, mosquito control and the life of fish larvae, the early development of North American fish, studies on the Central American ichthyofauna, marine fishes in eastern North America, Panama and Peru, and revisions within the herring family. Furthermore, Hildebrand was involved in the standard work Fishes of the Western North Atlantic.
Works (selection)
The Fishes of the Fresh Waters of Panama, 1916 (with Seth Eugene Meek)
The Marine Fishes of Panama, 1923 (with Seth Eugene Meek)
Hildebrand, Samuel F.; Cable, Louella E. (1938). "Further notes on the development and life history of some teleosts at Beaufort, N.C.". Bulletin (24). U.S. Bureau of Fisheries. {{cite journal}}: Cite journal requires |journal= (help)
A Descriptive Catalog of the Shore Fishes of Peru, 1946