James Stewart was 30 in Mr. Smith Goes to Washington when he played the character 'Jefferson Smith'.
That was over 85 years ago in 1939.
In 1997 he died aged 89, starring in 146 films in his career, 119 of those after Mr. Smith Goes to Washington was first released. If he were alive today he would be 116.
In Mr. Smith Goes to Washington, I think James Stewart looks: