Several things of a life-changing nature occur in Adam Cooper's life the second after he signs the muster that would officially make him part of the militia of colonists that will try to defend themselves against the British troops that plan to move in and attack Concord.
The first occurs shortly after staring right at the eyes of his father after signing up to join the militia. Moses Cooper, Adam's father, has never been kind nor supportive to Adam. In fact, he even forbids Adam from joining the militia as he did not see his son being "man enough" at age 15 to do so. Tired of his father's criticism, Adam goes against his will, and signs up. There, something new happens: the fact that he signs the muster makes Adam feel empowered, and more like a man. No longer feeling like a child, he takes a good look at his father, who stares back at Adam in what seems to be shock. As the two take a good look at each other under these circumstances, the son realizes the magnificence that is the presence of his father; a strong, confident, and a good leader despite of his flaws. Likewise, we will find later that the father saw in his son someone "ready" and "willing" to take these serious matters into his own hands. He no longer sees Adam as a child, either. Unfortunately, Moses will be killed hours later, and will never get to see the triumphant return of his son.
How was it, I wondered, that I had never noticed before what a strikingly handsome man he was? How was it that I had seen in him only the strength of his over bearance and not the shewed strength of those massive brown arms spread on the desk with the white shirt sleeves rolled high and carelessly? It was no wonder that men listened to him and heeded his words.
The second occurrence is Adam facing personal conflicts. He is in every way a pacifist, and his actions in the field demonstrate so. In the climactic moment of the novel, he even falls asleep as the battle goes on, taken by excessive exhaustion.Yet, Adam has to face his dislike of war; he has to do what he has signed up to do. He and his cousins do conduct themselves in battle with great courage. However, it is evident that this day comes as a total surprise to Adam, whose very foundation is obviously shaken, particularly when his father is killed without even confronting the British troops. The colonists were willing to speak, but the British were brutes and willing to kill. That was the reason why, eventually, the huge Revolution would come.
Why no one on our side had even thought of firing a gun, because when you came right down to it, we didn’t like guns and did not believe in them.
Having been through the battle, falling asleep, and then waking up are symbols of the passage from boyhood to manhood. As Adam wakes up, he directly asks where the conflict has moved to, and is willing to finish what he started.
All resolved, he returns to his home where his mother gives him the same treatment he would have given his father. Now, Adam is THE head of household. He is given a huge supper, he is treated to the admiration of others, and his brother looks up to him. As the man of the house, and having lost his father the day before, he is given candles to go reconcile with him (his body) and say a last prayer.
Notice that the novel is not divided by chapters but by each moment of the day. This is to show the longitudinal series of changes that come over Adam, and how in just one day he went from boy to man; from colonist to soldier.