James K. Polk – IQ 143.4

Almost everyone agrees that James K. Polk was undoubtedly one of the most influential Presidents in American political history. Not only he tackled significant territorial disputes, but he also brought a real change in fiscal policy and the banking sector. Besides, Polk is credited for the emerging victor in the Mexican war and even managed to maintain peace with the UK.

Even though James fulfilled his campaign promise of staying President only for one term, the job’s stress left him in poor health. It seems that even a high IQ of 143.4 did not increase tolerance for all that stress!