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The tie-in to ASJ is that it's about Quantrill and his raid on Lawrence, Kansas. Jesse and his gang join up with Quantrill and the movie follows Jesse as his qualms about what's going on get stronger and stronger. It's interesting to see how the movie depicts the raid, though I suspect it's not especially accurate.
The Lawless Breed, from 1952, has Rock Hudson in his first starring role, as John Wesley Hardin. What's interesting about this movie is that Hardin is referred to as "the fastest gun in the West" and that he goes up against three brothers named Hanley. They aren't especially good guys, though. After seeing The Lawless Breed, I read some about Hardin, and I don't think the movie was particularly accurate in its description of Hardin's life; however, it was fun to watch.
Other ASJ connections: Both movies were produced by Universal and Bud Westmore did the make-up on at least one of them, possibly both--he also did make-up on ASJ.