Trivia

Charles Chaplin re-shot the scene in which the Little Tramp buys a flower from the blind flower-girl 342 times, as he could not find a satisfactory way of showing that the blind flower-girl thought that the mute tramp was wealthy.
--Source: The Guinness Book of Movie: Facts & Feats, Page 142

This was Charles Chaplin's first film made during the sound era. He faced pressure to make the film as a talkie, but such was his popularity and power in Hollywood that he was able to complete and release the film as a silent (even though with recorded music and sporadic sound effects) at a time when the rest of the American motion picture industry had converted to sound.
--Source: Chaplin in the sound era: an analysis of the seven talkies, Page 55

The boxing scene is a variant of the fight-fixing gag that was ultimately discarded from The Circus (1928).
--Source: Chaplin in the sound era: an analysis of the seven talkies, Page 58

Chaplin in 1931 : “Because the silent picture has been temporarily pushed aside in the hysteria attending the introduction of speech by no means indicates that it is extinct or that the motion picture screen has seen the last of it. City lights is the evidence of it.”
--Source: Chaplin in the sound era: an analysis of the seven talkies, Page 59

When the film opened in England (February 1921), the Irish playwright George Bernard Shaw joined Chaplin. Charlie wrote that he admired Shaw's intellect but was uncomfortable with his view that all art should be propaganda.
--Source: Chaplin and American Culture, Page 131