How does jack Winthrop change during the war ?

Jack Winthrop was a British Colonial and friend of HawkEye, Chingachgook, and Uncas (although they don't explain how they met we can assume this based on the way they talk with each other at the beginning of the film in John Cameron's Cabin). I'm not sure why you asked this question considering he is only in 4 scenes of the movie. It was never said how or why or even if he changed during the war. He was raising a Colonial Milita to help fight the French in the North, he believed England was still their sovereign (Masters if you will) and even though during the meeting with the British Leuitenant, Hawkeye and John Cameron said it was pointless because France was not their enemy but Englands alone, he still left to Fort William Henry with others to fight.

We see him again talking terms with General Webb in Albany, then twice more at Fort William Henry. He is last seen escaping with a few others back to their homes to check on their loved ones after hearing the news from Hawkeye of John Cameron and his family's murder by Ottowa and French "coureur de bois" (Allied to the French). If you pay attention to faces of the other Colonials you will see the rest were killed in action during the massacre after the British left Fort William Henry, it takes a couple of times of watching that part to see the actors and realize they were vaguely killed off during the intense fighting. (Orchesrated by Marquis Montcalm and Magua earlier on) This is a very in depth answer I know, only because I have such love for this film ever since my History teacher showed it in class, I know ever single line from the film even the other languages because I've seen it over 1000 times. It really is a masterpiece.

I know this wasn't the answer you were looking for, but the question itself didn't make sense given my explanation. You might be thinking of "How did Major Duncan Hayward change during the war" He was a conditioned British soldier who thought nothing of those he deemed "Beneath him" But the ravages of war and senseless deaths happinging around him is kind of the push that made him give his own life for Hawkeye and Cora at the Huron Villiage where he was burned at the stake, he knew Cora was in love with Hawkeye and not him, and he forgave them for it. Hawkeye shot him in the head as a mercy kill, so he wouldn't have to suffer and die from smoke inhalation, although the time it took Hawkeye to get to his rifle was plenty of suffering for Duncan while he was in the fire. Even still, it was mercy. Had Duncan not been with Hawkeye and the others his world view would not have changed and he would have let Hawkeye take Coras place on the fire in a heartbeat. I hope I helped some, even though you posted this 8 months ago haha. I hope you see this answer and take something from it. Have a great day.

, Noah