Julius Krug was born on November 23, 1907 in Madison, Wisconsin. He earned his A.B. (1929) and A.M. (1930) at the University of Wisconsin and his D.Eng at the Colorado School of Mines (1949). He worked at number of business jobs around the United States before becoming the Secretary of the Interior for President Truman in 1946. He held this post until 1949, when he returned to his private life as a business executive. Krug died on March 26, 1970 and is buried in Arlington National Cemetery in Washington, DC.