More than 150 years after the death of their grandfather, a pair of grandson's belonging to the 10th President of the United States John Tyler are still alive. They are both the son's of of Lyon Gardiner Tyler Sr., the president’s fourth son. To put that in perspective, that means three generations of Tyler men have managed to span 227 years and counting. Lyon Gardiner Tyler Jr. was born in 1924 to Lyon Gardiner Tyler, the son of the late president and still lives in Tennessee. John Tyler, born in 1790, grew up on a Virginia plantation, became a lawyer,...