Short answers, pulled from the story.
City Lights was released on the 7th of March 1931. It had no spoken dialogue and was technically a silent film, though it was released with a synchronized musical score and sound effects rather than in complete silence.
Charlie Chaplin wrote, produced, directed, and starred in City Lights as his iconic character the Little Tramp. Virginia Cherrill played the blind flower girl and Harry Myers played the eccentric millionaire.
The main leitmotif for the blind flower girl is "La Violetera" ("Who'll Buy my Violets"), written by Spanish composer José Padilla. Chaplin used the song without crediting Padilla and lost a lawsuit over it, which was decided in Paris.
Principal photography on City Lights ran from the 27th of December 1928 to September 1930, nearly two years. Chaplin shot 314,256 feet of film to produce a finished picture of 8,093 feet, a ratio of approximately 38.8 to 1.
City Lights earned $4.25 million in worldwide rentals during its initial release. The American theatrical rentals alone reached an estimated $2 million, a quarter of which came from its twelve-week run at the George M. Cohan Theater in New York.
The American Film Institute ranked City Lights 11th on its 2007 list of the greatest American films and named it the best romantic comedy of American cinema in 2008. The Library of Congress selected it for the National Film Registry in 1991, and in the 1952 Sight and Sound poll it ranked second among the best films of all time.