During World War I he served on advisory boards for the United States Department of Agriculture and the American Food Administration under Herbert Hoover .
Jeffers served on the New Jersey Board of Agriculture from 1916 to 1927 .
During World War I Jeffers served on advisory boards for the United States Department of Agriculture and the American Food Administration under Herbert Hoover .
Jeffers served on the New Jersey Board of Agriculture from 1916 to 1927 .