The film made branded Margot as a major talent, and in the following years she starred in a string of critically acclaimed pictures, such as Black Christmas (1974), The Great Waldo Pepper (1975), 92 in the Shade (1975) - directed by Thomas McGuane, who was also her husband for a brief period - and a somewhat prophetic tale of self-resurrection, The Reincarnation of Peter Proud (1975).
Her new agent hooked her up with a little-known director named Richard Donner. He was going to be directing a film called Superman (1978), and she auditioned for and secured the leading female role of Lois Lane. That film and Superman II (1980) were to be filmed simultaneously. After the success of "Superman" she took on more intense roles, such as The Amityville Horror (1979) and Willie & Phil (1980). After that, Margot did numerous films, television and theater work throughout the 1980s, including Superman IV: The Quest for Peace (1987). When the 1990s erupted with the Gulf War, Margot found herself becoming involved in politics. She made a stir in the biz when she spoke out against the military for their actions in Kuwait. She also appeared in a cameo in Donner's Maverick (1994).
Margot has had continued success in film and on TV and even had a guest-star role on a newer version of Superman which fans al know and love called SMALLVILLE! PLUS SEE HERE IN THE NEW ROB ZOMBIE film H2 (Halloween II)!!!!
Margot is currently writing a book and tours the world meeting fans at conventions and also is a highly sought after speaker for the Mental Health field appearing a numerous seminars to educate people on mental health issues.