Andrew Johnson – 138.9
Following the assassination of Abraham Lincoln, Andrew Johnson was elected President of the United States. The President of the United States of America did, however, become the first President of the United States of America to be impeached in the country’s history. This criticism has been leveled at him because of his plans to return the seceded states to the Union while simultaneously refusing to provide protection to former slaves. This initiative was met with fierce criticism in the United States Congress. The cherry on top of it all was the fact that his IQ was only 138.9.

Andrew Johnson