James A. Garfield knew and taught both Latin and Greek, and he was the first President to campaign in two languages (English and German). He was also ambidextrous. Stories emerged to the effect that Garfield would entertain his friends by having them ask him questions, and then writing the answer in Latin with one hand while simultaneously writing the answer in Greek with the other. However, specifics of these stories are not documented.
us president that could write with both hands
James A. Garfield