Troup was born in Houston County, Georgia, to Alexander Lawton Miller and Katherine Flewellyn Burt. He graduated from West Point in 1902 and married Rosa Coffin the next year. He served with the American Expeditionary Forces in World War I in two of the cavalry regiments and made the U. S. Army a lifelong career, rising to Brigadier General in World War II. Troup's connection to John T. Willis is unknown. John was born to Anna Boyd Wilson and John Turner Willis, Sr., in Augusta, Georgia. He worked as a salesman, like his father, for most of his life. Some time after May 1917 he enlisted in the A.E.F. Air Services and served as a second lieutenant in the 29th squadron. He apparently married about 1928 and may have had a son before he died.