The Phineas Gage died at the age of 36. Here is all you want to know, and more!
Biography - A Short Wiki
After suffering frontal lobe damage as the result of a railway construction accident in which a long, metal rod completely pierced his skull, brain, and face, Gage spurred discussion within the fields of neurology and psychology about the role of different areas of the brain in determining personality.
The children of Hannah Trussell and Jesse Gage, he and his four younger siblings grew up in Grafton County, New Hampshire.