Machismo can’t easily be defined, yet moviegoers can always sense when it manifests on the big screen. It has often materialized in the form of charismatic (read: cool) men who incite a mix of envy, admiration, and attraction in both sexes. In the 1960s, four of its most prominent practitioners parlayed their skills into cinematic immortality. They came from differing backgrounds and career trajectories: Steve McQueen had garnered attention on TV, Lee Marvin had exercised stage chops, Charles Bronson had toiled in journeyman roles, and Jim Brown was an NFL icon. Crossing over to the big screen, Brown broke down barriers as an African-American action star; Bronson carved out a distinctive taciturn persona; and McQueen and Marvin wrestled with audience expectations as well as their own drives and demons. Their respective paths sometimes crossed onscreen, as their roles took them back to WWII, into the West, and through 1970s grit. So saddle up, strap in, and clench fists for a wild ride with these tough guys.