Grew up on Manhattan's Upper West Side
Found a job in Universal Pictures's export department in New York; became friends with Irving Thalberg, secretary to company boss Carl Laemmle
First film as assistant director (to Jack Conway) "Quicksand"
Joined the short-lived trade paper "Zit's"
Worked as freelance journalist on several New York newspapers and magazines before becoming the managing editor and complete writing staff of the Broadway weekly, "New York Amusements" (date approximate)
Chance meeting with Irving Thalberg (now head of production at MGM) resulted in Marx's moving to Hollywood to become story editor for MGM where he supervised a group of writers that included William Faulkner, F Scott Fitzgerald and Moss Hart
First story made into film, "Student Tour"
First screenplay credit, "A Night at the Opera"
First credit as producer, "The Longest Night"
Left MGM for a year when the B-picture unit he headed was dissolved; joined Samuel Goldwyn (date approximate)
Became story editor for Harry Cohn at Columbia
Produced 13 films for MGM including "Lassie Come Home" (1943)
Served as executive producer on Desilu series, "December Bride" and "Those Whiting Girls" (1955) during the early 1950s
Produced several TV series, including four "General Electric Hours" shows, "Broken Arrow" (1956) and "Northwest Passage" during the 1950s
Hired by MGM as its first executive producer of TV on "The Thin Man" and "Northwest Passage"
Began fulltime writing career during the 1970s
Served as consultant on TNT cable documentary, "M-G-M" When the Lions Roars", broadcast in March