In soldiers hearts, what were the congressmen and their families doing sitting on top of the hill above the battle? what happened to them?

In Chapter 5 of "Soldier's Heart", Charley witnessed from his first battle that the Congressmen and their families were on the hill. They had drove from Washington to picnic and watch the battle from a safe distance. They most likely returned to Washingston after the battle.

most cajuns resided in acadiana, where their descendants are still predominant

what is the question you are trying to ask?