On June 30, 1924, Calvin Jr. had played tennis with his brother on the White House tennis courts without putting on socks and developed a blister on one of his toes. The blister subsequently degenerated into sepsis. Calvin Jr. died a little over a week later at the age of 16.[21] The President never forgave himself for Calvin Jr's death.[22] His eldest son John said it "hurt [Coolidge] terribly", and psychiatric biographer Robert E. Gilbert, author of  The Tormented President: Calvin Coolidge, Death, and Clinical Depression, said that Coolidge "ceased to function as President after the death of his sixteen-year-old son". Gilbert explains in his book how Coolidge displayed all ten of the symptoms listed by the American Psychiatric Association as evidence of major depressive disorder following Calvin Jr.'s sudden death.[23] John later became a railroad executive, helped to start the Coolidge Foundation, and was instrumental in creating the President Calvin Coolidge State Historic Site.[24]
Coolidge was frugal, and when it came to securing a home, he insisted upon renting. He and his wife attended Northampton's Edwards Congregational Church before and after his presidency.