Sir John Craig's will stipulated that his successor was to be chosen by the board of directions from his four sons once they had all come of age and one could distinguish himself.

[3][1] As president, John David oversaw Eaton's expansion further west, acquiring Spencer's in British Columbia in 1948.

The store also expanded beyond its traditional downtown locations and began opening in suburban shopping centres during his tenure.

On 9 August 1933, Eaton married Signy Stefansson at Kawandag, his family home on Lake Rosseau.

He met Signy in Winnipeg while she was a student at the University of Manitoba and he was working at the Eaton's Portage Avenue store.

[8] Plagued with ill health throughout his later career and retirement, Eaton died aged 63 from pneumonia on 4 August 1973 at home in Toronto.