@Pain66 These portraits clearly are not from the year of 1776. At least not most of them, as Thomas Jefferson and John Marshall would be looking pretty rough if they were 20 and 33 and looked like that.
But still, I am not surprised that they were young men when the revolution happened, as they would need to be at the peak fighting age to make it through the war (regardless if they directly fought or not).
It does show that men were much different then versus now.