[2] His father was William Sanderson McCormick (1815–1865) and mother was Mary Ann Grigsby (1828–1878) of the Hickory Hill estate in Virginia.

His father managed finances for the family agricultural machinery business which became International Harvester until he died in an insane asylum in 1865.

After she was widowed, his mother had sold her share of the family business to his better-known uncle Cyrus McCormick.

A plaque was later affixed to his 1869 room, which was numbered 46 East Lawn, where the first Kappa Sigma meeting was held.

[6]: 353–356  He first worked for McCormick Brothers & Findlay, and then started his own business selling insurance and real estate, with offices in Chicago and New York City.

Together, they had seven children:[2] See Chaim M. Rosenberg, The International Harvester Company: A History of the Founding Families and Their Machines (McFarland, 2019).