Fighting Mad is a 1976 film directed by Jonathan Demme, about an Arkansas farmer played by Peter Fonda who uses Guerrilla tactics against corrupt land developers evicting him and his neighbors in order to stripmine their land.
In making the film, producer Roger Corman analysed three other recent low-budget rural action thrillers that had been big hits: Billy Jack (1971), Walking Tall (1973) and Dirty Mary, Crazy Larry (1974). He deduced they had three things in common: a hero with an off-beat sidekick, an unusual mode of transport and an interesting weapon. This is why the Peter Fonda character travels on an old motorcycle with his toddler son and uses a crossbow.
(Summary from Wikipedia)