Final answer:
The great adventure star of the 1920s known for his athletic and optimistic persona was Douglas Fairbanks. He became one of Hollywood's biggest stars, famous for his roles in films like 'The Mark of Zorro' and 'Robin Hood'. Other contemporaries included Rudolph Valentino, John Barrymore, and Lon Chaney, each famous for different on-screen personas.
Step-by-step explanation:
The great adventure star of the 1920s who was known for his athletic and optimistic persona and became one of Hollywood's biggest stars was Douglas Fairbanks. Although Charlie Chaplin was indeed the top box office attraction with his iconic tramp character, when it comes to the archetypal swashbuckling hero of the 1920s, it was Douglas Fairbanks who embodied this role. Fairbanks starred in classic films such as The Mark of Zorro (1920), Robin Hood (1922), and The Thief of Bagdad (1924) that showcased his physical prowess and charm, distinguishing him as the quintessential adventure star of that era. Rudolph Valentino also had a remarkable impact on the film industry with his alluring performances, but he was more of a romantic icon than an adventurer. John Barrymore and Lon Chaney were also prominent figures in Hollywood during the 1920s, but they were known for different types of roles: Barrymore for his dramatic performances and Chaney for his transformative character roles in horror films.