Anspach starred in several Broadway and off-Broadway shows, including as the female lead (Sheila) in the musical "Hair". The musical ran for 45 performances at the Cheetah Theatre. She was in a play with Al Pacino while at the Actors Studio. Anspach first came to prominence in the 1970 film "Five Easy Pieces", directed by Bob Rafelson and starring Jack Nicholson. Vincent Canby of "The New York Times" called her "one of America's most charming and talented actresses". She followed this with a supporting role in Woody Allen's "Play It Again, Sam" (1972) and a more prominent role in Paul Mazursky's romantic comedy "Blume in Love" (1973), alongside George Segal and Kris Kristofferson.