Here is the full list of all 14 Tin Star achievements.
Become the most despicable Marshal.
Bring the law to the frontier.
Don't put limitations on people.
Hang Marshals Steele and James.
See things through in Lander county.
Kill the bear.
Love more than most.
Betray Carson, Caraway, and Schmidt in one play-through.
Your word is your bond.
Your feats are legend though your name is lost.
Don't accept anyone's rules.
Ride that grizzly bear!
You are a true friend to the Indians.
You are the Marshal that brought order to the frontier.