John Wayne, born Marion Morrison, played football at USC (from 1925-27, nicknamed Duke) and appeared in more than 70 films (mostly B Westerns for little Republic Pictures) before he became an overnight star (grin) as the Ringo kid in director John Ford's Stagecoach (1939), which lost the Best Picture Oscar to Gone With the Wind (1939). His next noteworthy role was in Republic's most expensive film ever, Dark Command (1940), which was also their most successful (e.g. box office) ever. Throughout the 40's and 50's, Wayne starred in dozens of well known Westerns (several of which were directed by Ford) and (WWII) war films which helped establish him as a top box office draw, spanning more years than most of his contemporaries. He got to play opposite many of the leading ladies of his day (including Claudette Colbert and Marlene Dietrich), but most frequently with red-headed beauty Maureen O'Hara.
He received three Academy Award nominations: one for Best Actor as the tough Marine Sergeant Stryker in Sands of Iwo Jima (1949), one of his more overtly patriotic (rah rah propaganda) films, besides his Vietnam film, The Green Berets (1968); one as the producer of The Alamo (1960) (e.g. Best Picture nominee) in which he played former TN congressman Davy Crockett; and his Oscar winning Best Actor performance as Rooster Cogburn in True Grit (1969).
While you could easily select any number of his (particularly) war films or Westerns for their American themes, most of them aren't as patriotic as say James Cagney's Yankee Doodle Dandy (1942). But the characters he played (e.g. their morals and values) earned him recognition as:
the archetypal American of our country's formative period: honest, direct, decisive, solitary, and reverent; one whose faith in his own ability enables him to take action when it's needed, and whose belief in justice spurs him to right wrongs when they're discovered. (He) played that character-or variations on it-in almost every movie he made, and it became so much a part of him that most people couldn't separate the real Wayne from his screen persona. - as Leonard Maltin so aptly put it. Personally, I refuse to accept him as one who "didn't age well"!
My favorite films of his, in reverse chronological order, include: The Shootist (1976), The Cowboys (1972), True Grit (1969), McLintock! (1963), The Longest Day (1962), The Man Who Shot Liberty Valance (1962), Rio Bravo (1959), (the un-PC) The Searchers (1956), Hondo (1953), The Quiet Man (1952), Rio Grande (1950), Sands of Iwo Jima (1949), She Wore a Yellow Ribbon (1949), Red River (1948), Fort Apache (1948), and They Were Expendable (1945) (though this is really Robert Montgomery's film).