If you like O Brother, Where Art Thou? You'll probably also like Fool's Parade (1971)

Another enjoyable crime/road trip Southern Gothic story. Great performances by Jimmy Stewart, Strother Martin, a very young Kurt Russell and George Kennedy's slimiest, evilest role. Also with David Huddleston who would later work for the Coens as The Big Lebowski as a secondary villain. Not as sweeping a story as OBWAT, but in my opinion, The Coens had to be aware of Fool's Parade when they made this.