William J. Nicholson was born on March 2, 1924 in Chicago, Illinois. Growing up, he was interested in engineering, aviation, and aeronautics.
After graduating from high school, he heard that the University of Chicago was hiring, so he decided to apply. He worked as a laboratory helper at the University of Chicago's Metallurgical Laboratory ("Met Lab") during the Manhattan Project. In 1943, he left the Met Lab, and turned down job offerings for Sites X,Y, and Z (later revealed to be Hanford, Los Alamos, and Oak Ridge). Instead, he aspired to join the Navy Air Force, and he passed the examination to join.
He ultimately served in the European Theater with the Army Air Force, before being discharged in late 1945. He was also deployed to Sioux Falls, South Dakota, and Pyote, Texas, during his service.
After the war, he went back to school at the Illinois Institute of Technology. Nicholson then began a long and successful career in the oil industry. This included serving as a Director of Operations for Amoco Chemicals for Europe, the Middle East, and Africa.