Hang 'Em High (1968)

Jed Cooper (Clint Eastwood) is accused by nine men of killing one of their neighbors and stealing his cattle. When he fails to convince them of his innocence, they hang him. Fortunately, there is U.S. Marshal Dave Bliss (Ben Johnson), who is in the area, and saves Cooper, who is then brought to Fort Grant for trial. Eventually, it is discovered that the man Cooper bought the cattle from was, in fact, the killer. Cooper is released, but still wants to get the nine men who hung him. Judge Adam Fenton (Pat Hingle) warns Cooper about taking the law into his own hands, who responds by saying that he knows the law, being a former lawman. The judge then offers Cooper a job as a Marshal. Cooper, while in a town picking up a prisoner, discovers one of the nine men and kills him after he draws on Cooper. When he returns to Fort Grant, Cooper learns that another member of the mob has turned himself in after learning of Cooper's innocence. He provides Cooper with the names of the rest and Cooper leaves to round them up. On his way to bring in the lynchers, Cooper is sidetracked by a report of another rustling and murder. Upon finding the rustlers, one of whom was in the posse that lynched Cooper, the posse wants to lynch them, but Cooper insists that they need to be tried and is left to bring them in on his own. Following a difficult road back to Fort Grant, the remaining members of the posse that hung him try to buy him off, then decide that the only way they can live free is to finish the job and kill him.

IMDb: https://www.imdb.com/title/tt0061747