Which film made John Wayne an instant mainstream star?

Marion Mitchell Morrison (born Marion Robert Morrison; May 26, 1907 – June 11, 1979), known professionally as John Wayne and nicknamed Duke, was an American actor, filmmaker, and Presidential Medal of Freedom recipient. He was among the top box office draws for three decades.

Wayne was born in Winterset, Iowa but grew up in Southern California. He lost a football scholarship to the University of Southern California as a result of a bodysurfing accident, and began working for the Fox Film Corporation. He appeared mostly in small parts, but his first leading role came in Raoul Walsh's Western "The Big Trail" (1930), an early widescreen film epic which was a box-office failure. Leading roles followed in numerous B movies during the 1930s, most of them also Westerns, without becoming a major name.

It was John Ford's "Stagecoach" (1939) that made him an instant mainstream star, and he starred in 142 motion pictures altogether. According to one biographer, "John Wayne personified for millions the nation's frontier heritage."