The Metamorphosis of Norma Jean Mortenson was created for the exhibition Homage to Marilyn Monroe, at the Sidney Janis Gallery, New York, December 6–30, 1967. The show, a benefit for The Association of Mentally Ill Children in Manhattan, also included works by John Chamberlain, Chryssa, Marisol, Claes Oldenburg, James Rosenquist, and Andy Warhol.
Although Indiana had not been particularly taken with the actress while she was alive, he became fascinated with Monroe when he began learning about her life and fate. His fascination was increased by the numerical coincidences in her life, particularly the dominance of the numbers 2 and 6: She was born in 1926 and died in 1962, lived in 12 (6x2) foster homes, played her first dramatic role (in Don’t Bother to Knock) at the age of 26 in 1952 (2x26=52), and died in August (2+6). The numbers 2 and 6, as well as the letters spelling her birth and stage names, appear in circles in rings around her image, recalling the dials of rotary phones and alluding to the telephone she was found clutching at death.
Writing about the painting to his German gallerist Alfred Schmela, in a letter dated October 30, 1967, Indiana noted “I am very pleased with my painting and it represents a divergence in my own style which will give it a certain surprise value.” The work is one of his few in acrylic, and on December 31, 1967, he wrote to Schmela, regarding the medium, that “a new feeling was gained . . . a warmth and glow from the pastels which I had never striven for before.”