 William McCormick Blair's mother, Anna Reubenia "Ruby" McCormick (1860–1917), was a daughter of the agricultural machinery manufacturer William Sanderson McCormick (1815–1865) and a member of the illustrious McCormick family.Her grandfather was Robert McCormick (1780–1846), who invented a mechanical reaper.William graduated from Groton School in 1903, and received a BA from Yale University in 1907.