Harrison Ruffin Tyler – the last living grandson of the 10th president John Tyler – died this past Sunday evening, May 25th at the age of 96.

Harrison Tyler was a businessman, a chemical engineer and a passionate preservationist. In the mid-1970s Harrison purchased, and spent years restoring, Sherwood Forest Plantation, America’s longest framed home located in central Virginia. The home was acquired by John Tyler in 1842 and served as the former president’s home until his death in 1862.

Harrison Tyler, courtesy CSPAN

Harrison Tyler’s father, Lyon Gardiner Tyler, was born in 1853 and was the thirteenth child of former president John Tyler (in office from 1841 to 1845). At the time of Lyon’s birth, the former president was married to his second (and much younger) wife Julia.

Lyon Gardiner Tyler

John Tyler was 63 years old when Lyon was born…and Lyon Tyler was 75 years old when Harrison Ruffin Tyler was born.

Former president John Tyler

The fact that Harrison Ruffin Tyler lived to the age of 96, and that his father and grandfather each had younger second-wives, helps solve the mathematical mystery of how it is possible the 10th US president – born in 1790 – had a living grandson until May 2025.