Leslie Groves was not a pleasant man to work for, but if you wanted to get something done, he was the man to accomplish the seemingly impossible. He demonstrated this twice during World War II: spearheading the Manhattan Project and overseeing the construction of the Pentagon. A ruthless driver of men, and a born problem solver, he managed to build the Pentagon under budget and in sixteen months, a project that was estimated initially to take four years.
Major General Kenneth Nichols, who worked under Groves summed up the man:
First, General Groves is the biggest S.O.B. I have ever worked for. He is most demanding. He is most critical. He is always a driver, never a praiser. He is abrasive and sarcastic. He disregards all normal organizational channels. He is extremely intelligent. He has the guts to make difficult, timely decisions. He is the most egotistical man I know. He knows he is right and so sticks by his decision. He abounds with energy and expects everyone to work as hard or even harder than he does. Although he gave me great responsibility and adequate authority to carry out his mission-type orders, he constantly meddled with my subordinates. However, to compensate for that he had a small staff, which meant that we were not subject to the usual staff-type heckling. He ruthlessly protected the overall project from other government agency interference, which made my task easier. He seldom accepted other agency cooperation and then only on his own terms. During the war and since I have had the opportunity to meet many of our most outstanding leaders in the Army, Navy and Air Force as well as many of our outstanding scientific, engineering and industrial leaders. And in summary, if I had to do my part of the atomic bomb project over again and had the privilege of picking my boss I would pick General Groves.