1. Mount your horse / Ride to Dewberry Creek
Get on your horse and go with Charles to Dewberry Creek.
2. Search Dewberry Creek for any inhabitants / Investigate the body
When you get there, you will start searching the area. At some point, Charles will find a body. Get close to it to investigate it.
3. Search the camp
You'll notice a camp nearby. Go to the camp to examine it.
At first the camp seems to be empty, but when you examine the crates next to the wagon, it will turn out that a mother and her children are hiding under the wagon. Unfortunately, they are Germans and only the daughter speaks little English. She will tell you that their father has been kidnapped.
At first Arthur won't be willing to help them, but Charles will convince him to do so.
4. Mount your horse / Follow Charles
Charles will try to track down the kidnappers. You can follow him or you can use Eagle Eye to look for a trail on your own.
Follow the trail until you reach the camp. Charles will find this place much better then previous one for a new camp for your gang.
5. Search the camp for the settler / Free the captive settler
In the camp you will find a tied settler lying on the ground.
When you start to cut him free, and pull the gag out of his mouth, he will try to warn you that it is an ambush. Unfortunately, it'll be too late for a warning, because the enemies will start shooting at you.
6. Defend against the attackers
Keeping in mind the requirements for a gold medal, find a cover and use Dead Eye to get the required accuracy and five headshots.
7. Free the captive settler / Return the settler to his family
You can now cut the settler free without any hindrance.
Charles will go back to the gang to inform Dutch about the new place for a camp. You should get on your horse, take the settler with you and try to get him back to the other members of his family as quickly as possible. If you want to earn a gold medal then you have 1 minute and 40 seconds to do so.
As a token of gratitude for saving his life, the German settler will hand you a gold ingot. Then he will leave and the mission will be completed.
This was the last story mission of the second act of the game. After completing it, your gang will move its camp to a new place - Clemens Point.