In 1913, Mayo went on a three-month tour of Europe, including London and other foreign capitals. This tour was a trip of both business and pleasure. On August 20, he returned to Paintsville. An elaborate reception was given by John E. Buckingham, a close friend of Mayo. Citizens from all over the area went to welcome back "Johnson County's most prominent resident". Unknown to the guests at the reception, Mayo was already suffering from Bright's Disease. It was soon released to the public that Mayo was ill.