Eddie is told to stay away from "the roaring forties", meaning the Times Square (42nd St.) area of NYC., then and for many later years known as an entertainment district and for its' wild night life. The free spirited decade of the 1920s can be described in the same vein, as "roaring".
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 The Jazz Singer in 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.