What was the first all-talking full-length feature film?

'Lights of New York' is a 1928 American Pre-code crime drama film starring Helene Costello, Cullen Landis and Eugene Pallette, and directed by Bryan Foy. Filmed in the Vitaphone sound-on-disc sound system, it is the first all-talking full-length feature film, released by Warner Bros., who had introduced the first feature-length with sound 'Don Juan' (1926 film) two years earlier, to utilize the Vitaphone sound-on-disc sound system with only a synchronized musical score, sound effects, and no spoken dialogue. Then introduced another feature-length Part-Talkie 'The Jazz Singer' the previous year. The film, which cost $23,000 to produce ("B" picture), grossed over $1,000,000. The enthusiasm with which audiences greeted the talkies was so great that by the end of 1929, Hollywood was producing sound films exclusively.