SAGE was founded in 1965 in New York City by Sara Miller (later Sara Miller McCune) with Macmillan Publishers executive George D. McCune as a "mentor"; the name of the company is an acronym formed from the first letters of their given names. SAGE relocated to Southern California in 1966, after Miller and McCune married; McCune left Macmillan to formally join the company at that time. Sara Miller McCune remained president for 18 years, shifting to board chairman in 1984 (and still retains the title of executive chairman). The couple continued to develop the company together until George McCune's death in 1990.