What U.S President refused to use the telephone while in office?

It's Calvin Coolidge - the thirtieth president of the United States.

Coolidge’s presidential style (from HistoryToday.com):

The means by which Coolidge learned of his elevation to the presidency set the tone for his administration. He was staying at his father’s home where there was no telephone and no electricity. A messenger delivered the news. His father, as a local notary, swore him in by the light of a kerosene lamp; he may have got the words of the oath wrong. This was a very nineteenth-century scene and Coolidge effectively operated a nineteenth-century presidency. His view of administration was that it should avoid harm rather than promote good. It was the job of the president to enforce the law as it stood not to change it. This led to his being what has been called a ‘minimalist politician’. He never did what someone else could have done instead. He said, ‘The way I transact the cabinet business is to leave to the head of department the conduct of his own business.’ Indeed when his Secretary of Labor, James L Davis, asked him to read some papers and offer his advice, Coolidge said to the secretary bringing them, ‘You tell ol’ man Davis … if he can’t do the job I’ll get a new Secretary of Labor.’ Coolidge held regular press conferences but they were small and he only accepted questions in advance. If he didn’t like the questions he wouldn’t answer them.

Coolidge’s reluctance to speak did make life awkward. He attempted to control Congress by holding working breakfasts but his silence made them self-defeating. Invited Congressmen left no wiser as to what was expected of them and indeed came up with more and more imaginative excuses not to attend - although when Coolidge had Senator Johnson’s claim that his barn had burned down investigated, it was found to be true! Similarly he received his appointees’ reports in silence and often sent them away without a word. They never knew whether he had listened or not, although perhaps months later they might recognise their suggestions in something he said or did as president.

Perhaps H.L. Mencken summarised best the Coolidge presidential style when he said Coolidge’s ideal day ‘would be one in which nothing happens’.

Learn more about the life of Calvin Coolidge, or 'Silent Cal,' at Biography.com and HISTORY.com.