Jack McCall (George Montgomery) is a Southerner, but joins the Union Army in the Civil War. When he is tricked into giving out the location of headquarters, he's tried as a spy and sentenced to death. He makes good his escape, but Wild Bill Hickok (Douglas Kennedy) and Bat McCall (James Seay) kill his parents to seize his plantation and money. On the run getting into one scrape after another while trying to prove his innocence, he hooks up with the beautiful Rose Griffith (Angela Stevens) who becomes his faithful ally. He still has hopes of clearing his name when he hears Bat and Hickok are now are after gold in the Dakotas...

It has always been fashionable in Hollywood to take characters of legend and fashion plots around their name that had absolutely nothing to do with the lives these people led. Jack McCall Desperado is an almost Kafkaesque revision of western lore with Montgomery as McCall who is a good and misunderstood man. The real-life historical Jack McCall was, by all accounts, nothing more than a murdering punk. This entry plays fast and loose with history, with McCall as the framed good guy out to get villain Hickok. the time frame is all askew, starts in the Civil War and moves rapidly to Wild Bill's murder, which in reality took place in 1876, eleven years later.