The Good, the Bad, and the Ugly (1966)
What? You say it's not even associated with Sergio Leone's other Clint Eastwood spaghetti westerns because it has actors playing completely different characters (Lee Van Cleef!) from their roles in Fistful of Dollars or For a Few Dollars More? Pshaw. GBU is clearly set during the Civil War before the other two films and Eastwood's Man With No Name specifically acquires the iconic wardrobe that his character made famous in the other films.