Conant taught chemistry at Harvard, and performmed important research in the field of Physical Organic Chemistry. In 1933, he accepted an appointment as the President of Harvard University, which he continued as until 1953, although between 1941 and 1946, Conant served as chairman of the National Defense Research Committee. He served as US High Commissioner to Germany and Ambassador to Germany from 1953 to 1957.
While President of Harvard he oversaw a process of transformation that saw Harvard become America's preeminent university. He introduced significant changes in the way students were admitted, and faculty were hired, and created the general education program, and the Harvard Case Histories on Experimental Science. He was active throughout his career on issues of education, not just for Harvard, but for the nation, and later, internationally.
Conant died in Hanover, New Hampshire in 1978.