Calvin Coolidge (1872-1933) was the 30th President of the United States. He was often called "Silent Cal". He was Vice-President under Warren Gamaliel Harding until he died in office in which case he was sworn in to the Presidency by his father who was a preacher. He was sworn in for his second term by William Howard Taft, the 27th President. This was the first time a former President swore in a sitting President and it was the first Presidential inauguration to be broadcast on radio.