[citation needed] A graduate of St. Louis Country Day School (now Mary Institute and St. Louis Country Day School), McDonnell completed his Bachelor's and Master's degrees in aeronautical engineering at Princeton University in 1960 and 1962, respectively.

[citation needed] He earned an MBA from the Olin Business School at Washington University in St. Louis, which also awarded him an honorary doctorate in science in 2006.

[2] After marrying his wife Anne in 1961, McDonnell began working for MAC as a strength engineer on Project Gemini the following year.

[3] He was instrumental in founding McDonnell Douglas Finance Corporation in Los Angeles and ultimately becoming a vice president of the division in 1968.

[10] McDonnell resides in the St. Louis area, and enjoys traveling and tennis as hobbies.