Chisum is based on the Lincoln County Wars, so features Lawrence Murphy, Billy The Kid, Pat Garrett and Chisum (JOHN Chisum) himself (played by John Wayne). There are disputes over land, lawlessness, and trying to do the right thing by the law, when the law itself is corrupt. Another classic western!
The amazing thing for me, is how it was not so long ago when the USA was so lawless. The picture at the top is of George Coe, who was involved in the fighting, lost a finger at the Blazers Mill gunfight, and was (obviously) still alive just before the Second World War, as this photograph was taken in 1934.
As l said - amazing.