 So standing in the family sitting room with the family Bible on the table, Coolidge raised his right hand before the light of a kerosene lamp and took the oath of office, becoming America's 30th president. Asked later why he thought he had the authority to administer the oath, Colonel John Coolidge said, well, nobody told me I couldn't. The next morning, Coolidge visited his mother's grave for inspiration and then took the train down to Washington.