McGhee was born on March 10, 1912, in
Waco, Texas, the son of a Waco banker. He studied at the
University of Oklahoma, graduating with a degree in geology in 1933. He was initiated into the Oklahoma Kappa chapter of
Sigma Alpha Epsilon fraternity at OU. For a time McGhee worked for
Conoco, on a crew that made the first oil discovery on the
Gulf Coast using
reflection seismology. He was awarded a
Rhodes scholarship, and earned a doctorate in physical sciences from
Oxford University in 1937. Back in the United States he became vice president of the National Geophysical Company, where he managed reflection seismology surveys in Cuba. On his return to Texas, McGhee found employment with
Everette Lee DeGolyer's oil services company
DeGolyer and MacNaughton, scouting oilfields and marrying DeGolyer's daughter Cecilia. McGhee described Cecilia as "the most beautiful and richest girl in Texas." In 1940 McGhee established his own company, the McGhee Production Company, and soon discovered a major oil field at
Lake Charles, Louisiana, which made his fortune. ==Wartime service==