[3] Whitaker was acting chairman of the department of physics at New York University until 1942, when he joined the Manhattan Project's Metallurgical Laboratory in Chicago during World War II.

[3] In September 1942, Arthur Compton asked him to form the nucleus of an operating staff for the X-10 Graphite Reactor that was to be constructed on Oak Ridge, Tennessee.

[6][7] The first permanent operating staff arrived at X-10 from the Metallurgical Laboratory in Chicago in April 1944, by which time DuPont began transferring its technicians to the site.

[4] After the war's end, Whitaker left Oak Ridge to take up the post of president of Lehigh University on June 1, 1946.

In 1959 he initiated the Centennial development program, which raised over $22 million for faculty salaries and construction that included the University Center,[1] and the Whitaker Laboratory, which would be named in his honor in 1966.